Search by type could be great, yeah. Another suggestion, though probably more complicated at this stage, is "marking" items. For example marking all scrolls, arrows and potions with a Star, then filtering by Stars, to show all combat-items.
Adding another one here so to not open an entire new thread for one small suggestion - make barter window identical to inventory one. It's always an issue (to me, at least) organising your inventory properly. But then after I do, and I go to sell some stuff, everything's all over the place and unrelated to how I ordered it.
I find myself opening my inventory, taking mental notes on which stuff to sell, then quickly begin bartering and sell the stuff before I forget.
