D.J.
I think the screaming is one of two things... it's either a ploy for attention, or he's just excited to have found something he can do like that, though at 23 months I tend to believe the first. Either way, I agree that you should just close the door and leave him alone while he's screaming. Tell him before you leave that you will come back when he stops. Listen for him to stop for at least 10 or 15 seconds the first time, then go back in and tell him "Thank you for not screaming. Now I can play with you." If he starts again, immediately leave the room and do it all over again, staying away longer and longer after the screaming stops. I can almost guarantee that this will solve the screaming problem within a day or two.
As for bedtime, have you tried just letting him play until he falls asleep? What time is his bedtime? If it's fairly early, I'd say just let him play a while. Only give him a few toys, and most likely he will get bored after a while and fall asleep. And always keep those same toys in the crib. Once he's played himself to sleep a few times, they will be less and less interesting and he should go to sleep faster and faster. No guarantees on this one, but that's what I would try.