I can't settle the argument about who's a douche and who's not, but I can tell you how to half ass soundproof a door on the cheap. Having been in several garage bands, its a skill I've picked up.
Basically just get ass loads of egg cartons and layer the inside of your door with them. Hang a thick blanket or, better yet, a rug or piece of carpeting over it.
Half-ass soundproof door. Note the half ass. This is by no means perfect, but it helps a lot, and is pretty cheap. You can sometimes luck out and find a metric shit-ton of egg cartons behind grocery stores, if not just get them...somewhere.....
If you have gaps under the door just block them shits up with some towels. I used that trick back in my teenage herb smokin' days. Unfortunately for me it doesn't block smells, but fortunately for you it helps lessen sounds
Won't do shit