How to turn off ghosts permanently (or atleast in the room)?
Is there something like /opt ghost... And no, I don't want you to tell me that I can press b.

You can't, only way to do so is b, or g, which will only turn off your own ghost.

but you would need to press that every turn

No, you don't. It does it for the entire match.

g is for the entire match i think, and b is every turn

Press B. I never knew you could disable ghosts for the whole match but, now I do! But yeah, press G or B.