Oh man, adjusting up Common, Single Prefix, and Dual Prefix and 0'ing out broken seems to be working perfectly to purge 95% of broken items from the game.

Is there any risk in setting these up high of making the monsters never drop MIs or blues/purples, or is that something that's handled in a sense by the monster drops on an individual level (replacing whatever else they'd carry)?

I really, really appreciate your rapid response and help on this - it's pretty much exactly what the wife and I were looking for. More aggressively equipped mobs are tougher.