1. Are the uncomfortable grunts the characters make allowed to be muted?
2. Are you allowed to be listening to a different song over it if it doesn't obscure the audio too much?

If you're talking about muting the character grunts via the options menu, that's perfectly fine (as long as you have literally any game audio it's fine) and as for music, it really shouldn't cause any major issues unless the game is inaudible.

alright thanks