I love it!
I actually just wrote a post with my own suggestions, and I also had some ideas about the inventory system. I think they could be combined with yours, and I'm curious to know your thoughts on them!

I really like the idea of usable items in a belt slot that will be used up next battle. This would be a great way to create 'sinks' in the game that we can spend items on.

After all, with loot being found over time we need something to clean up the amount of loot stored in people's inventories too, lest they overflow eventually