As for the AP it could keep their AP in combat as well.
I don't use filters; I really like to order and maintain clean my inventory in this kind of games and (fortunately) there are a lot of objects in this one, this is its great strength but at the same time its great debility because such variety is really hard to store, plus a lot of objects needed often, even using the bar as shortcut for swap items they don't return to their original position.
All I want to transmit is that this game needs a more "clean" inventory system.
-Many games has slots in character screen for tools too (not only weapons are useful in RPGs). It would be nice to have our gold, shovel, magnifying glass, lockpicks, etc in dedicated slots.
But that would be a little spoilerish. I'm the kind of player who doesn't look things up but experiment. If you point all the tools to me, half the puzzle is solved.
I see it more as a hint, and this huge game really needs hints...