There will be a 'Charm Quality' listed in the equipment's stats (in orange text, under the weight, above the damage or armour value) if you can add a charm to it. Once added, charms can not be removed or replaced.
Spell books can randomly appear in merchant or NPC inventories (and bookcases), but if you don't get them soon after, they will disappear. Merchant inventories reset after about 10 or 15 minutes real time.
You may have collected quite a few axes and other equipment you are not going to use, etc, which you can use for trading. I separated my loot into crappy/broken stuff to trade for potions, then equipment with full durability that could be traded for the most value, and then equipment that needed to be repaired.
I don't think there is a way to disable the damage or experience text. I barely noticed it if I wasn't specifically looking for it.
