Can I back out of a roommate situation with my best friend?
Why do you want to backout?
He laughs and plays and sleeps so fucking loud and he plays so much fucking video games. He fucking annoys the crap out of me.
I can see why his behavior would annoy you. It's a good idea to take a vacation together first to get to know each other and agree on a set of rules before becoming roommates.
The plan is still to move out after 4 days.
I think you should follow your gut. Living with someone you do not get along with well can damage your relationship.