Adam,
You can work on projects without using the RSCM, the only thing you can not do is have multiple people work in the project at the same time, this includes working in Xpedition and xDX Designer with multiple people. I have also seen it lock up the project as well but that is easy to fix just go into the project\database\cdbsvr\ folder and delete the address.adr file and the project will open after that.
Good luck,
Neal