My only comment on your party is that in IWD there are not very many good short bows, which is all your thief can use. I might consider going with slings. But it's by no means a deal-breaker.

1) You might consider the Unfinished Business mod, if you want extra content. I also like the infinite stacking and bottomless bags of holding mods, but many consider that a 'cheat'. I don't, as to me it just makes inventory management much less of a living hell. YMMV.

2) I'd actually advise doing it after completing the main campaign. Makes more sense from a roleplay perspective, IMO.

3) TotL can be pretty brutally difficult, so I'd advise being fairly high level. Maybe go for that one before heading off to the Sea of Moving Ice.

Not really. They level faster, but get fewer spells per level. They're absolutely fantastic as secondary casters though, so I'd suggest considering going with a 5th party member as a Bard and specializing your mage. It's a pretty solid addition, IMO. Perhaps not exactly iconic, but if you're actually considering ditching a mage for a Bard, then the strict iconic ideal is out the window anyway, right?

Yeah, you can get a lot of stuff at gibberlings3. However, I find their site isn't laid out all that well for searching out fixes/tweaks/mods for particular games, so it might be easier to just google first and then choose the gibberlings3 link in the results.

Well, I think I've already compromised the iconic theme by taking a paladin instead of a fighter, but I can really use a paladin's specials with this party. Besides, a paladin is still a warrior.

As for the bard, I just like bards. Someone needs to sing the songs of the party's exploits, right? I'm tempted to take one on as a 5th, but I want to keep the party size small. I'm also doing a BG saga run with a max party (for the interactions and whatnot), but controlling six people is a drag. Four is a lot more fluid.

I've already put the party together. I don't have the patience for chronic rerolling but I managed to get ridiculously lucky with my paladin (18/00, 18, 18. 10, 13, 18). The others are ok, too. Let's just hope it all works out.

Actually, there is a place in Kuldahar that sells scrolls. Not that's exactly the most noticeable location possible; when I played, I didn't realize it even existed until I had gotten back from completing HoW. If scrolls are still a concern, specialty mages get to put a new spell in their books with each level they gain.

The problem is that his stock is highly limited. When you first encounter him, he doesn't have any spells above 2nd level in stock. By the time he restocks, it's close to the end-game and you may have 6th or 7th level spell slots, and the 4th level spells he's added to his inventory are actually below your pay-grade.

Doesn't Orrick restock after Dragon's Eye? That's not too far into the game. I think there's another change later on as well.

I only recall him restocking once, but I could be mistaken. Exactly when it happened isn't the point; rather, by the time he restocked I'd already attained so many additional levels that his new stock was insufficient for my needs. I had unusable spell slots right up until the final chapter (when there was finally a level-appropriate cache of scrolls to be found as treasure).

Yeah, I just did a quick google search to see if I recalled correctly. He restocks after Dragon's Eye and then again in Chapter 4. But the second restock only adds a couple things that weren't there after DE, and can be easy to not notice that it's a restock.

And yeah, if your mage is leveling fast due to a smaller party size (or playing on the Insane or Easy setting), then you'll definitely be leveled beyond what he has to offer by the time he restocks.

Orrick's shop inventory is replaced when you start chapter 2 and when you start chapter 4.

Ok, well, needless to say, my mage is going to be way ahead of the game (no pun intended?). I'm currently in the last tomb in the Vale of Shadows and it's going pretty well so far. My paladin has racked up about 75% of the kills, but the other party members are helping. As the game goes on, the level gap between this party and a six person party is going to increase. So, the cleric and thief are likely going to be able to keep up with the THAC0 curve. Also, the thief is definitely pulling his weight with sneak attacks. They don't do enough damage to rack up kills, but they really soften them up. He is the one I have to micromanage the most to make it work.

I am kinda bothered by the mage thing, though. It irks me that I can't use him to his full potential. I'm half tempted to Dalekeep in one spell for every level, that way, when he gets access, at least he'll have something. Hey, that makes me think of something. Ok, if I were to DK in one spell for every level, what should I pick? Here's the thing though. I don't want the best spell for every level. I'm not trying to cheese out. What I want is a mediocre, but still useful spell. Just winging it off the top of my head, I'm thinking:

3 Protection from Normal Missiles
4 Confusion
5 Domination
6 Power Word, Silence
7 Seven Eyes
8 Mind Blank or Power Word: Blind
9 Nothing, I'll just have to earn these

Are these middle of the road enough, do you think?

I could be wrong, but I have a feeling that those spells would be lost every time you level up. Keep that in mind. Power Word Blind is cheese -- too powerful.

For the spells, I'd go this way:

3) Monster Summoning 1: the monsters will be useful cannon fodder, and summons are always a bit of a help, but the ones you get with his spell are weak and won't serve to be overpowered.
4) Confusion is a decent choice, or perhaps Monster Summon 2 or Otiluke's (this last may be argued to be too powerful, but it's only a single target and can be used to buy some time for an injured party member or to take a mob out of the running for a few rounds)
5) Good choice
6) Good
7) all spells here are pretty powerful, so no worries, I guess
8) I'd sub in Mind Blank here.
9) Yeah, only 2 ninth level spells, so I'd hold off.

Thanks for the spell tips. Level 3 is taken care of by a dispel magic scroll I found, and I'll be taking your advice on the rest.

edit: removed a question I figured out on my own.

I'm at the Severed Hand now and this party is going swimmingly. The paladin is racking up 75% of the kills, and the cleric has been a solid backup tank. The halfling thief is even pulling his weight as an archer, though being limited to short bows is hurting. I've found two really good long bows, and only a single magical short bow (+1). Still, he's keeping a respectable THAC0. The mage is kind of dead weight, sometimes. The best thing he does for the party is cast web (and turn the thief invisible so he can scout and search for traps). He has level 5 spell access, but the only spells he has is Mental Domination (useless against all the undead), and Oracle (which is fun for a laugh, but otherwise, whatever).

I'm really looking forward to getting though this and starting IWD2. The same traditional setup with 3e rules is going to make an even more well-rounded party.