Unless you shield your building completely, there is no way to determine if the signal is coming from in the room or from outside without triangulating the signal and there isn't a guaranteed way to force the phones to connect to your device instead of the actual cell tower.
Depending on jurisdiction, this may or may not even be legal since it could cause interference with people passing by who just happen to get caught in your net. I don't think you would be able to tell the cellphone numbers since that is established by the carrier, but you would be able to tell the cellular radio's identifying numbers. You wouldn't be able to tell who they are calling without breaking through the encryption (which would almost certainly be illegal.)
So in short 1)Not without triangulating the signal and even then unlikely to be reliable. 2) Unlikely, though you could identify the physical phone being used. 3) You could identify that a particular phone (but not phone number) is making a call. 4) You could tell how much time the connection stays alive. These all depend on them remaining connected to your repeater however which again, is not guaranteed unless you can block out the real tower.