Hi, thanks for sharing the bugs! Not sure how I missed the mouse issues but I'll make a fixed version to sort them out. It would be amazing if you could get me a copy of the log file after it crashes in a black screen in co-op so I can see what happened.
And I agree, the inventory system is definitely due an overhaul. We reworked a bunch of UI stuff in this version with the goal of getting ready to improve that sort of thing, and I think that's how the mouse bugs snuck in.