So, I spent a good portion of today dicking around with potions. The good news is that the overwhelming majority of what I want to do looks easily editable in the .bin - tedious, but doable. The bad news (maybe) is that I haven't tested it out yet and I may very well be incorrect in that assumption, at which point I sort of have a big mess that I'm left with no other choice but to dump into Grayface's lap.
Anyhow, here's what I've got going on.
First off, red and blue potions being on equal footing - even at the very beginning of the game - is problematic. Blue potions are far much more useful since you can get a lot more HP restoration out of them by casting Heal. The only advantages of red potions is that they can be quaffed endlessly in mid-battle and they don't use up valuable blue reagents - nice, but not enough. My solution is to make green the new SP restoration potion, which serves both to make basic Alchemy a more useful skill to obtain and also to make all three reagents valuable in the early game.
Next up, many white potions tend to show up well beyond the point where they would have been useful. This coincides nicely with most of the layered potions acting as either inferior versions of the spells they emulate or, in the case of Haste, extremely broken versions. Resistance and weapon-enhancing (Freezing/Flaming/Shocking/Noxious) potions are now layered concoctions, whereas most of the previous layered potion effects are now exclusively available in spell or scroll format.
(Also, it was *really* weird having single-character versions of party-wide spells like Shield and Stoneskin. Just sayin'.)
Divine Power and Divine Cure being on the same level doesn't have the same problem as their weaker counterparts do purely because of Divine Cure's strength - it's much more potent than anything you can cast as far as sheer healing strength goes. Divine Restoration got booted purely because I didn't feel like invalidating all of the status-curing potions before it, and Stone to Flesh is now a white potion instead of a black one. Because reasons.
Black potions, finally, are nice and all, but they really don't have much going for them aside from being able to make pure potions or rejuvenation on demand. In fact, that's really all there is in the black potion line for the most part, so I tried to think of what other spells might do good as black potions (and lend some much-needed allure to Druidism). I figured Raise Dead and Pain Reflection were the two spells that would work well as potions, so that's what I went with.
Of course, that last bit above is the one thing I *can't* do on my own - and so is yet another item for the list of things I'll need to bed Grayface to help me out with.
"You don't have to be a vampire to die like one... *****." -Simon Belmont