OP you are a douche. You don't like the guy, you took a gift from that benefited you. You accepted a gift from a guy you don't like that benefited you AND you imposed part of the payment (visits) on your roommates.
4 nights is too much? LOL. This is college dude. Unless you establish some house rules, people will take your open ended invitation literally. If you really only meant a few nights, then you should have clarified in your original deal. He is not in the wrong for wanting to play with your Xbox; a host is suppose to supply reasonable entertainment to their guest. He gives you a bike, but you don't want him playing your Xbox? Again, you are a douche. You used this guy for a bike, and now don't want to "repay" him for it.
Other people have covered the party thing well. It was an open invite, and he asked the hostess. Do you require your roommate to ask for permission to attend parties? If, no, they why is this guy the exception?
You invited this guy into your life. If you don't want him around, then you have to man up and either a) set some ground rules about the house visits or b) remove him from your circle firmly but gentle.
What exactly did you mean he could come over at visit at night? Did you mean the weekends? Invites only? Did you just mean for him to have a couch to crash on so he didn't have to drive home on late nights?
It is up to you to set down with him and say:
"Hey, I know told you to come over, but that is before I knew how much homework I was going to have from classes. On nights XXXX I really need quiet for me and my roommates to study. If you want to come by and chat or play Xbox, this day and time would be better."
"Dude, I sorry. I know I said you could come over a few nights, but I am now uncomfortable with the arrangement. I don't know you well enough yet to be having you coming over so much. And my roommates are not happy with the arrangement either. I didn't clear it with them. I sorry, I don't want you coming over to my house anymore for awhile. We can still chat on campus. So that there are no hard feeling, I want to give you the bike back."