This is stated in the FAQ post:
Q: Can I edit my game after submission? A: You can fix critical bugs, but leave a note explaining the changes. Avoid altering the game during the voting period.
I would say fixes 1-3 are completely okay as they are not about adding new functionality or features - just making sure your game works as intended.
Fix 4 is up for debate but I would say that is ok too as it really does not have anything to do with your game.