A couple things I've noticed recently:
* Involuntary Teleportation causes trouble in the shop, because it always sends you to the starting point. This is very frustrating, especially when I wanted to buy a particular downgrade to get enough points for Alternative Medicine, and it was literally impossible to get to that part of the store before teleporting back. Apparently InvTele affects Volcano too, teleporting you inside lava shortly after the level start, because it also sends you to the starting spawn every time
* Alternative Medicine says it cures schizo, but doesn't
* Food Stamps doesn't appear to do anything? It's unclear if it's not affecting the "Shop Chance" display on stats, or if it's doing anything at all. Shop chance seems screwy in general