I think there should be some nice items that are not really based on min/max characters and could indeed benefit toons who were not rolled as optimized by newer players. Essential they are items that factor stats that aren't just UMD to use.
An example would be a wizard cloak that requires 18 dex because it's made from a magical fox tail and is a pain in the arse to put on or trip yourself on. Lets say you remove a +dex item and drop below 18 dex with the cloak equipped. Instead of de-equipping the item like UMD items, you find yourself randomly tripping while moving/casting and suffer a -2 BAB bonus to melee.
I'm thinking of Artemis Entreri's sword that required not only tremendous skill to weild but an incredible amount of willpower to master w/out the glove. While willpower isn't a D&D stat it correlates pretty closely with wisdom when you look at in-game saves and how certain characters save vs. hold spells in books. Artemis' sword fried people who didn't have the willpower to touch it barehanded. While we don't need to go to that extent there are plenty of ways to go about messing with people who fail the requirements, from instant random 2 blindess, bleed effects, poison damage etc.