Would I be cheating by:
- Changing the config settings to give me maximum hit-points on level-up and preventing saving throw auto-failure on rolling a 1?
- Spawning spell scrolls that do not seem to be available from the campaign's merchant stores, so long as I reduce my gold total to reflect the value of the scroll?
1. No to both. Among other things, before that hit point option was introduced people would simply cancel the level-up process and repeat until they got the maximum possible. It actually actually makes things fairer and many modules are tuned assuming you DO have max hit points -- otherwise the HP of the character could wildly, wildly vary even with the same classes/constitution/etc. The auto-fail on 1 is just an idiotic design decision and there's a reason they decided to throw in an option to change it. Keep in mind that also goes both ways -- enemies won't auto-fail either now. No 5% chance to insta-kill them with Death Magic or Dev Crit or whatever if their save is high.
2, I don't think that's cheating if you're doing it to learn spells as a wizard (because you might think that you could learn those spells from scrolls and pick other ones on level-up). If you just want to spawn in a bunch of IGMS scrolls when no store at that point of the campaign would even carry scrolls of that power, that's more questionable.
I think I may restart the campaign with a druid and play a sorcerer for an evil playthrough, picking only spells that were not introduced by the expansions. Although having said that, eyeball familiars are summoned by mages a lot. Incidentally, apart from Eltoora's sidequest in chapter 1, are there any other class-specific (or alignment-specific) quests in the OC?
Ultimately the OC is going to be really easy if you have a clue with or without the new expansions spells, for what it's worth. I don't think there's any other class-specific or alignment-specific quests in Chapter 1, at least, but there are several quests where some classes or alignments get easy/automatic access and others have to manage a persuade check. Chapter 2 has some Druid specific stuff for sure. Forget beyond that.
When facing the Swords of Never I think I was about level 8; after casting Haste, a few ILMS and Scintillating Sphere spells did the trick. Didn't even need Stoneskin and I left my Henchman behind (usually more trouble than they're worth in boss fights). Was the last encounter before leaving City Core for Helm's Hold.
Yeah, well, Fireball would have achieved the same result as Scin Sphere (unless the Swords are immune to Fire but not Electric?) and ILMS isn't game-breaking at all, Maximized Magic Missile would be 80% as good at level 9, for example.
I give nearly all my level 1 characters boots of haste, dr 5 slashing/bludgeoning/piercing resist and ring of regen +1 when I start a new game. Simply stated, play how you want. It's only cheating if you think it is.
In the context of how most people (including the OP) think of cheating, that would be cheating. Like you said, though, play how you want -- but for people about the OP not wanting to disrupt the balance of a module, doing what you do would defeat that goal.