1) Make all (crafting?) items stackable
2) Adjust the weight of some of the crafting items, like dust
3) Colored backpacks
4) An additional "junk" tab where you can move items that you want to sell - alternatively a "keep" tab in your inventory for items that should not show up at the vendor
5) Don't make gear that is store in backpacks disappear from the quickslot after use