From what I've read, most everyone removes the compressor and all the freon, it could leak down the road and that would not be good.
As for the hole, you can fit all your cords in one hole. And you seal it up, some people use the spray foam in the can and some just patch it with foil tape. You should put a fan in for sure and a light is just a personal option. If you do go with a light try to go with one of those real small fluorescent one that do not give off much heat. That's what I plane on doing, one with a glass door.

Good luck,

Dave