Always a pleasure. Enjoying the progression.
(you pointed it out, so sorry, I had to find a bug in it) .. ;)
On the note of the key bindings, I see that you have spent some time on that. Here is what I noticed right off the bat, quick test..
I went in, changed the Inventory to TAB, and it warned me about over writing Stats.. so I clicked "overwrite" .. done, left the menu system..
When I click TAB now, I get, the inventory, but when I click TAB again to close Inv., you can see the player stats window also flash.. it appears that you should add to your "overwrite" routine, to nul out the item that we are overwriting.. as I currently have two actions, assigned to TAB.. stats and inventory..
ps -- of course I was able to fix it by going to stats, and changing it from TAB to "P"..