You can sort things into multiple chests, or other containers, if you wish.
There are already hotkeys for potions, just open the potion menu, hover the mouse over the potion icon and hit a function key.
Tutorial-Changing F1-F12 hotkeys to different keys

Other than bug fixes (parts of the Tingalf quest can get broken if it is done too much out of the expected order, weight bug, etc), I'd say the main thing would be game balance. The game tends to get easier as it progresses, and gold becomes readily available. Perhaps if the range of potential stats was narrowed a bit for higher end items (dragon set, etc), some people would be less likely to reload to get the best possible equipment / loot, so would not end up overpowered and very rich at the end of the game (though that is only part of the problem). If you are not going to add stuff to the wastelands, its size could be cut down (at the beginning of the wastelands I was in the mood for some hack and slash, but in the Black Ring dungeons I started running past stuff I didn't have to fight to get to the main buildings).

The game could use a couple more non-sword unique weapons consistently in the game, for those not playing warriors, or not wanting to look like standard warriors.

minor things:

Add a loading screen tip about right clicking on the menu bar interface to minimize it to 3 lines (for health, mana and stamina), and right clicking on the lines to restore the full bar.

Add a warning when first entering the place of sacrifice to not open the tombs, or put a password on it so you need the book from the cursed abbey to get in.