Sadly this game doesn't have as much resources on the internet as HoMM 3 did. And the manual doesn't help. So...

Q1) Is heroes' movement points no longer dependent on the speed of the slowest army? So all heroes have equal movement, regardless of army type?

Q2) What is the difficulty between difference levels?

Q3) (minor, but I can't figure it out) In the end of level stats, what does "in sight" mean? Like "Resources gathered - in sight" and "Resources gathered - total"?

Well... This is probably old news to many people here, but apparently there are community manuals that give tons of details
http://www.heroesofmightandmagic.com/heroes5/game_manuals.shtml

That's really great effort. Though I prefer wiki format to pdf, those things are really detailed and easy to navigate. Kudos to the authors for the excellent job.

So:
Q1) Yes, units have absolutely no effect on hero movement. For details on adventure movement, check the manual linked above.

Q3) is not answered.

And now the bad news...

Q2) The "Normal" difficulty should actually be called Easy, since it gives you huge bonuses. You get 3 times as much starting resources as the computer, and the AI is very handicapped (for example building only every second turn, and never casting spells higher than level 3). How on earth is that normal???

On Hard difficulty, you get same starting resources as the computer, and AI plays to the best of its ability (there are some minor details between Hard and Heroic AI...)
However...
In the campigns, the neutral stacks are 30% bigger, but experience per unit killed is reduced so that the total amount of experience gaind is the same.

I really hate this. It's the same story as with HoMM4. I would really really really love to play on a difficulty where you get no advantage over the AI, but with neutral stacks being normal. But asgain it's not possible here. WHY??? Sorry, but this is really ridiculous. Either make Normal difficulty exactly that: normal i.e. no one has advantage and creature stacks are normal size, or even better, make it 3 separate difficulty settings: starting resources, AI and neutral stacks.

I've only played haphazardly, and it has been awhile, but a quick note: (imp) Enlightenment is the best skill by far, with Logistics running a somewhat close second. Enlightenment gives you bonus experience (eh, sure), and +1 to a random stat (att, def, sp, kn) every other level when it is Expert level, effective retroactively. Logistics is simply extra move speed.

Also, note that you can choose which of your stacks get involved in combat. So you can grab those peasants without risking their money making in combat. Or you can keep your archer stack out of a battle where they'd be shot to pieces. If you lose the fight, all stacks that didn't participate ARE eliminated though.

Thanks. I discovered this, and it's pretty neat.

Another thing I discovered accidentally that I really liked, is that right-clicking on end-turn gives you information on the week. Even if it does nothing, some of the descriptions are pretty funny (Week of the Rabbit - "Not a good week to be a carrot").

I don't think they are talking about individual towns, more like each faction has a special ability. Each hero of that faction has the faction ability

Haven heroes can Train their human units at a Haven town to become higher tier troops for a fee. So you could train a Peasant into a Paladin with enough gold. The Haven ability also provides Counterattack, iirc.

The Dark elf ability allows their spells to pierce magic resistance/immunity. So Dark Elf damage spells WILL hurt a black dragon some. One of their buildings lets them use creature elemental affinities to deal more damage with their creatures and spells.

The Demon ability is summoning. Their ability allows their demon troops to summon extra stacks onto the battle field for free. A demon building will cause those summoned stacks to show up faster.

Sylvan faction has Favored Enemy.

Undead has necromancy.

I don't remember the rest off hand. More later; need to go for now.

Nope. Each single town has its own specialization.

I was really surprised when I came across it in the community manual, but I verified it and it's there.

For example, Ashwood has slightly better market rates. You can check it yourself, load level 3 of Haven campaign and compare the market rates there to what you should normally get had you 1 town only, while Strongbow (from Haven level 2) generates an extra bowman per week (which you can verify in the unit production).

I looked at the level editor and the town specialization is there. It's usually something small; like a small weekly income, better market rates, better thieves guild rates, +1 to luck or morale or attack or defense, -1 to enemy's luck... etc, stronger walls or towers, cheaper heroes, extra level n recruits.

But unfortunately you can't seem to see this ingame, short of guessing at it from the town description. The community manual has the bonuses for the default ones, but ultimately it all depends on the map maker who can give whatever bonus they want. The Haven town Dunmoor from Haven level 5 for example is not mentioned in the manual, though from its description it seems to have stronger towers of some sort.

Ah. Then no, I don't know where to find that (if it exists). I did a cursory look around in a custom game, but I didn't see anything there.

Is each secondary skill limited to 3 abilities. So if I took Pathfinding, Scouting and Navigation for example, I can no longer take Navigation?

Correct, each secondary skill is limited to three abilities. Some have pre-dependencies. The skill wheel has been invaluable to me for choosing the path I want. Find it here... https://www.celestialheavens.com/520

I can usually hit the windows key on my keyboard to minimise heroes games, so I often have this sitting there on the desktop. Notice that for different classes, there are sometimes different paths to the same thing - such as Mentoring.

I asume you are familiar with Celestial Heavens and Heroes Community? Also Maps for Heroes?

EDIT: Regarding Town Specialisation info from within the game, if you look at "Town Info" (F) from within the town Screen, (The far right button of the right hand set in Town view), and then read the town biography you get a clue as to what the benefit is.

For example, "extra mages are often available for hire" or "every few days an explosion is set off which brings in a few extra ore".

Not all Bios are so clear, but better than nothing. They are also editable, and must be defined by the mapmaker, so often in custom maps they are "undefined".

Adding on to what Bonzer said, it is possible for a hero to get locked out of some of the more advanced secondary skills, if they don't get the right pre-reqs. The Celestial Heavens skill wheel is incredibly useful in planning ahead.

So basically, my Demon Lord can no longer get Urgash's Call because he used up all 3 Logistics abilities on Pathfinding, Scouting and Swift Gating, and he still needs Teleport Assault for it.

I'm still doing the first level of Inferno campaign. Think I'll restart it to get Urgash's call.

Incidentally, while I enjoy the occasional base-less level when I play strategy games, I expect most of the levels to be normal ones where you build a base, and try to destroy the enemy's.

So far none of the levels in the campaigns was like that. At most you get 1 town, often no towns at all, and there are no enemy towns (except in the last level of Haven campaign, but that was one you weren't supposed to take over anyway).

Please tell me not all levels will be like that. That there will be levels where you start with a town, enemy(ies) start with a town, there are lots of neutral towns that you take over, and then yo utake over enemy towns. You know, like 90% of the levels in HoMM1-4!

So far this feels like the original King's Bounty and not a HoMM game. I liked it when I started paying it, but this is becoming ridiculous.

Thanks. I saw them in the community manual but didn't realize their importance.
I'm playing tahe game without any expansions, so my wheel looks slightly different. I'm assuming the one you linked to is for TotE installed?

There are 3 levels of circles, what do they mean? Is it that the outer one requires Basic, middle Advanced and inner Expert?

My memory is rusty, but from what I recall it varies. I think most of the Demon missions involved getting the primary hero to some location. At least one of those missions involved collecting a few towns before heading off toward the enemy town you need to take. Several were "get from point A to point B, while doing X along the way to cause/prevent some effect".

I think most of the Necromancer missions were a little more along the lines of what you would expect. Build your forces and go conquer. There are some special conditions involved (one map lets you convert wizard towns to necromancer towns), but that's the basic idea. The Dark Elf missions also tended to be "build and conquer" with the occasional "do X" thrown in (except the first mission, but that's spelled out from the beginning).

The first Sylvan mission was a defensive mission. Around this time life caught up with me and I lost access to the game for awhile. I haven't gotten back to it since then, so I can't speak for the rest.

Barbarian (Orc) is in the list, so it looks like TotE. Runelord is Dwarves, and came in the first expansion

I'm not sure what the 3 rings represent. They don't seem to represent increasing amounts of requirements, approximate level requirements (to get enough skills), or class specific skills (except the outermost ring, which might be basic skills available to every class), and some areas are quite crowded so it isn't just a spacing issue.

When I was playing, I'd just look at the available skills to see what I wanted, and click on one to see the exact requirements. Click on a space that isn't a skill to reset the wheel.

If I recall correctly, *most* of the campaign heroes are blocked from getting the center skill by virtue of their starting skills. I think I only ever got the Knight skill once with a secondary hero. The other blocking issue being that your skill options when you level rarely conform with what you need to advance on a planned progression.