I don't know about an on/off switch for items...
Just remembering to turn it "off" when killin' bandits, and "on" when killin' wyverns can be frustrating.
Also, what is that option good for when dealing with 2 or more types of mobs, some with desirable loot and some with simple junk? (wolves/goblins ; batrax,carrion eaters/orcs)
It dose nothing to reduce inventory management or increase fluidity of the game.
Gold autoloot on the other hand, is a good idea. Pinching those 3 gold out of the rest of the junk said ^ bandits ^ are carrying is getting tedious. Fast.
I wonder, is that kind of thing simple to code?