It would be nice if you could list the actual damage values for each of the weapons. With that, you would be able to more easily tell how much better an upgrade makes a specific weapon type without having to just buy it, find the weapon in a dungeon, and then test it on an enemy. For that matter, listing the special effects of upgrades, like more arrows per shot for the bow, would also be useful.
The game also seems to save after each composition so don't try and reload in order to get your item back after a failure, you will lose the item as well that way...