I used something for respecs, but I don't recall an item editor..
Btw, creating them could just ruin the game.. I preferred to find all legit. :P

You're kinda out of luck because there isn't really any such thing as good nightmare farming for hell. Nightmare is a cakewalk for many classes and builds but there is a massive difficulty spike between the end of nightmare and the beginning of hell. Doing a single-pass run through nightmare and going straight to hell isn't feasible for most builds and regardless of where you farm in nightmare, you're hardly going to get good stuff even for the early stages of hell. A catch 22 situation, basically. It can eventually be overcome by slow grinding and anal min-maxing / metagaming.

For nightmare farming, I found Mephisto runs to be ok but it takes too much time, you can do several Pindleskin runs in the same time (the skeleton miniboss from act V). If Anya's red portal is still open that is the fastest access to Pindleskin but if you activated the Halls of Pain portal then Anya's portal closes and you'll have to use the Halls of Pain portal but it's still faster than running Mephisto. You can of course change difficulty levels and restart the game in nightmare mode several times until you get an ideal layout that places the last portal before Mephisto in a convenient location where you can quickly run to him. Might take a few tries to get the randomizer to produce a good dungeon layout.

In act 5, you can also go to the first portal, run down the stairs to Shenk (the fat slave whip guy), quickly kill him and run back up, and then kill Eldritch who is very close to the portal as well (bit further up and to the right). Can't promise you'll get anything good anytime soon but Pindleskin/Shenk/Eldritch are the most convenient minor bosses who can drop so-so stuff. Andariel and cow runs are a waste of time on nightmare imho. The runes Andariel drops in nightmare aren't high level enough for cool rune words.

I managed to randomly get Immortal King's gauntlets, from Worldstone keep, while farming xp to level up... Dammnit, how much more happy i would have been with Necromancer's gloves, instead... Too bad i cannot trade; even if i find someone, no one can guarantee me they will have what i want, or that they will be willing to trade...

I found some good unique Demonhide boots, too, made a "stealth" runeword with Cuirass, maybe now i can start hell, after i ding 2-3 more level ups. All i need to is to survive farming the Mausoleum, another area 85 level which is also very near the rogue encampment, too. Next on my to do list are crafted items and hell rune collecting.

Found a 4 socket flail in Cow level for that Heart of the Oak, but of the 4 runes it needs, i have only Thul, lol. I have Spirit runeword on longsword, +1 skills runeword on helm, +1 skills runeword on shield and a great rare amulet +1 necro skills together with resistances and teleport charges, equipped. If i die now i will never forgive myself and i will never consider me a good old Diablo player, ever again... My merc is might aura act 2, with insight runeword, gemmed plate for +25% damage plus poison damage and a good exceptional plus ethereal item runeword for Nadir.

Here you have a nice dropcalc: http://diablo2.ingame.de/tips/calcs/dropcalc/#en

For your merc one of the cheaper runewords would be way way better than poison damage ;)

Btw. as Necro in HC it could be good to learn the KI Curses for hell to make enemies with ranged attacks nearly useless, else AD and maybe in HC DEC are the best ones for me .... and well, dont forget a good corpse explosion :)

I have learnt all curses already, and with my equipment in total, they are all at 6 skill level (pretty effective). Will try to Dim Vision Range attackers and Life Tap, or Iron Maiden, or Decrypify melee attackers, in Hell. But i need at least 1 more level, i am 71 right now... At 72, i will have maxed Skeleton Mastery, Raise Skeleton and Raise Skeletal Mage. With equipment, all of them get a +5 in total. I have corpse explosion too, but in hell, some monsters are immune to both physical and fire, sometimes :(

This reminds me... A good number of skills that are useful early on are utter crap later (like firebolt). Skeletons and Skeleton mastery is a dump skill. Put enough in until you can get golems, and raise the dead as shadows of themselves.

At least that's one thing they fixed in Zy-El, namely all skills are viable even at later levels...

Since 1.10 skels are the main use of Skelemancers, Golems are very weak, skels are really good and everything needs to be maxed there ... would have waited with mages though. AD is piercing phys resistance, so CE and skels are really good there together with huge radius of CE and when you play alone, everything is dead with one or few CE, so for me one of the most powerful skills. With insight you have more than enough mana to cast it over and over ;) ...

For hell better get some more +skills items to get stronger skels, this is where leoric helps alot in second slot ... i always moved to pindle, raised the skels there and then switched and had full power ... and for trading there always is d2jsp, although some of the people there are bad its better than ingame trading

Now i am 73. Reached Mausoleum in hell and i can farm it without the slightest problem! Gee, even 2 levels i dinged made a big difference! As long as i am in the back seat, no problem. Thankfully, you can Corpse Explosion without entering a room full of baddies and you can target dead corpses without direct contact! Feels like cheating! But damn, drop rates for hell are crap. No runes, no sets/uniques, no nothing... In nightmare, going from Rogue encampment all the way to Blood raven, earned me 5 runes, 1 unique and 2 set items... Hell is hard, you progress slowly, and damn, drops are cr@p. Even damaged and cracked white items appear, or chipped gems! Hell is CHEAP, D@MN!

Doh, reading this makes me want to restart Diablo II (without mods ofc)... Must... resist...

No no, don't resist! Let me help you and cast the lower resist curse on you! Seriously, the game is good! Too much dependency on runewords instead of sets and uniques like the old days, but it is really interesting.

Light weights! It was Multi-Shot + Lightning Enchanted that truly killed you. Man I hated that ability combo.

Character expiration seems to mostly be a thing of the past. I've left characters for a year or so and come back to play them. The "Character Expired" message displayed, but after I logged in with the character, it was fine.

Be aware that while it is in your weapon switch, it is not actually active. You need to have it as your current weapon to get the bonuses from it. You can use it to summon skellies at the higher skill level, then switch back and the skellies will remain summoned at the higher level. If it bumps the Summon Skelly skill enough to give you an extra skeleton, then the extra will die once you swap back (the skill is no longer being supported at that level).

By extension: if you see a skill shrine, then consider resummoning your expendable minions (not the Iron Golem) while the skill shrine is active. They'll still be at the higher skill level when the shrine wears off (while curses and such will go back to normal).

The 10 day limit is only for brand new characters, and you can leave your character sitting in one of the "Parking" games (or make your own) for 2 hours to push the limit to 90 days.

I'm pretty sure some of the ad bots get glitch rushed to Hell difficulty. Not much point in having one advertising in NM diff. I just wish there was a better way to filter to the spammed messages.

Most of the Ladder stuff is available in single player (not some of the events, though). In SP you can simulate having up to 8 players with the "/players x" line; the game will act as if there are 8 players in the game, though you are the only actual player.

Pretty much this.

You want a Summonmancer build? Max Raise Skeleton, Max Skeleton Mastery, 1 in Amp Damage through to Lower Resist, and just a few (1-5) in Golem Mastery and Summon Resist, then focus on Clay Golem. You can add 1 to Corpse Explosion (and pre-reqs) if you like. A few in Skeleton Mages and 1 in Revive if you like. Use the Act 2 merc with the Might aura. Make sure to keep your vitality high.

The Clay Golem gets insane HP, and the slow effect is epic even if the golem isn't high DPS. My merc is using Kelpie Snare for massive slow, +Clay Golem Slow, +Decrep, and Baal can't move and only occasionally attack. Amp Damage can break physical resistance for your skeletons to go to town while you sit back and stay alive, so use that most of the time.

They seriously toned down the Cow level drops some time back. Keep this in mind when deciding where to farm. Baal and the minions he calls up in the Throne of Destruction are pretty much the place to look now, iirc.

He's on the realms, so he can't preserve a mini-map path. That would work wonders in SP though.

The big draw for NM Andariel is the slim chance for SOJs, iirc. Shenk and Pindleskin both got their drops toned down a lot, but they are still very easy to access (I often run Shenk abd Eldritch when I start a game, just to see what they have).

Skeletons were indeed garbage way back. Now they are the summonmancer's bread and butter. Use Amp Damage and the Might merc with a golem. The Revived AI is simply too stupid to be reliable.

You need those chipped gems to start cubing runes of Thul and higher. Starts with various chipped, moves to flawed, and onward.

I know, but best place to farm chipped and flawed for rune recipes, is tombruns normal. Having chipped gems in Hell difficulty is a real pity and a real waste, in every sense... What i really need are flawless ones, since i am about to start crafting items... About my build, though, i have already maxed Skeleton Mastery, both skeletons (mage and warrior), i have opened ALL summoning skills (clay golem is indeed helpful in hell, coupled with decrypify sounds good as you suggested, and a holy freeze merc would top this combo, but would deprive you of "fuel"), i have opened ALL curses, i opened teeth and corpse explosion and i intend to max corpse explosion, too. With skillers and bonuses to all skills, even 1 point in somewhere, especially with synergies, makes a big difference.

Confusion surprised me a lot. It makes most enemies crazy and force them to infight between them, even breaking combos, such as the siege beasts throwing down the mounted hommunculi from their backs! There is nothing better than enemies not noticing you are there, unless they even fight among themselves, lol!

If you need flawless gems, then cube the chipped and flawed into flawless. :P
Cubing gems is my primary source of higher grade gems. Likewise, a great many of the higher level runes I have come from cubing the hordes of Tirs and Nefs and so on that I find.

With +skills, most of the curses only need 1 hard point; the gain from additional points just drops too fast to invest more hard points than 1. Corpse explosion probably shouldn't be maxed since the mana cost rises with the skill level while the damage is static (relative to the enemy that is exploded); after the effect reaches most of the screen, you don't really need more. This is also why I'd advise against putting more than a few points in the golem mastery related skills; it drops off too fast, and you just don't have enough skill points to max everything that would be useful. I'd suggest pointing more points into your golem than mages, but that might just be my personal preference.

I'll have to try out Confusion. I used to use Attract and Fire Golem bombing to generate my first corpse, once upon a time. Now-a-days I just walk into the Blood Moor and let my golem and merc make a body for me. The horde usually snowballs to capacity pretty quickly after that.

CE max is definitely a good decision, its THE killer in 1-4 player games and very effective even in 8 player games, most just overlook this skill. 1 in revives is great to get like 3 to 4 of them. For bosses get some crushing blow revives and tele to the boss then one step awy and soon dead he is.

Considering golems, clay is by far best, you can recast him whenever you want, so cast near a boss and he will get sloooow .... or cast away to check for ranged attacks, although more thna 1 point in any golem for me is quite useless as they arent there for damage and you can recast whenever you want.

Cow level NM has quite a chance of skillers and the cows are really easy with CE. If you have two diablos with two chars, you can kill the cow king with your necro while the other isnt in game and next games the other creates and opens portal and you can go in and kill cow king without the opener loosing his ability ;)