Problem: There are staffs that are pretty useless and are an instant drop from my inventory. (or i am an idiot and dont know why these are in the game ): Healing, teleportation, invisibility, protection, adrenaline. (why would you boost your enemies?) 

Solution:

Rare merchant: you can trade 3 staffs for a different staff of your choice.
Rare Mirror: There could be rare mirror on the wall. Shooting a heling staff on the mirror would heal the player.
Rare enemy :the big white knight that has glass shield, this could reflect magic (good or bad back to the player)
Rare  god statue that reflect magic back to you.

Problem: I need to pick up stuff to decide if it will improve my defense or not. For example I find "+2 shoes" and I cant remember if I have worse,same or better. So i press i  to check, realize I have a "+0 boots" and I have no idea which one is better. so I press g to pick up the shoe, realize my inventory is full, so I drop something, pick up the shoes , press e to equip and check defense, realize it is worse, so i equip my boots back and drop the shoes, and pick up what i dropped to free space for the stupid shoes in my inventory.  Doing this dance every time i find a defensive item is really boring after 20 levels.

Solution1: the grid or table on the top right could have numbers in each cell to let you know what defense it gives you. so you have a glove icon and a 7 next to , or in the corner of the icon to let you know its defense.
Solution2: the text that you see when stepping on an item could tell you if it is better or worse than what you have equipped. for example you have no gloves on and and step on a good one: "This is a +4 Iron Gloves (+7 defense)". same text could appear if you target it with the examine /pressing 'x' . The number could be red if worse, green if better and white if same defense than what you have now.

Very minor suggestion: using the backspace key for 'cancel command.' That way, I stop getting pulled out of full screen so much while playing on the browser version, lol