Fixed.

This still seems to exist - I just died with a score of -494849. There seems to be a problem with how your level of corruption is appraised - after I died, I was listed as "severely tainted by Chaos," but I hadn't even acquired any corruptions yet?

Same thing happened to my last character, the only source of corruption so far was stepping on one trap and the final score was on the order of -100,000. The end-game summary also said "severely corrupted by chaos".

Damn, damn, damn. It's all a consequence of the stupid "let's be slightly more precise and use a factor of 1000 to have more detailed AP effects" proposal... and my inability to find all the ensuing places where consequences derive. Never believe non-programmers when they say "it can't be difficult to..." :-(

Fixed more chaos point issues.

I'm sorry if you're referring to me, but I don't think I ever said it can't be difficult although the original suggestion may have made it look a lot easier to do than it was in practice.
And to be honest I really didn't (and actually still don't) have any idea about how many places corruption points are handled. Accumulating and removing corruption and scoring are the obvious places but of course those may have multiple instances like traps, background corruption in normal levels, background corruption in special levels, monster attacks, initial corruption, using corrupting weapon, pools (regular and stone circle), scroll of corruption removal, potions (cure corruption, raw chaos), carrying corrupting items, finishing quests (unicorns), using orbs, reading tracts, eating corpses or getting crowned as chaotic (and maybe some others too).
And I'm employed as a full-time programmer btw. :)

No. And nobody should feel guilty except for me as I keep failing to find all the special cases. It's just so frustrating ;-)