This sounds a little like how we did loot and world scaling on Dungeon Crawl.
It looks like you have things well in hand, but in our old database lies a hidden gem (or at least I think so) that you might get some use out of.
Jayseesee and I went through and meticulously categorized mobs in every zone. We had a several categories of importance from 'named' to 'zone boss' and a few in between. These flags were used to determine what tier of loot an NPC qualified for among our boss loot tiers. We also did quite a bit of legacy item buffing, but that information would be more difficult to extract.
Anyway, it's all here if you can make use of it.
Keep up the good work!