Eat, drink or sleep? Or does he not really need to, he just does it for the enjoyment?

He still has biological organs, so I'm pretty sure he does.

Interesting point-as some of his organs are still human, I daresay Beta Ray Bill still needs to eat, sleep (and go to the toilet if you want to get crude). It is also interesting that Wonder Man and the "new X-Man" known as Mercury also eat and presumably sleep not because their bodies require it- he is a being of ionic energy and she is a mutant whose body has transformed permanently into a form of organic metal not unlike that of Colossus- but because ingesting organic foods makes her "feel human" as Mercury explains to a teammate).

Terry