Not everyone has come with policing experience so I wouldn't worry about that. Training starts with the assumption you don't know anything.
At the minute for the people waiting on start dates, I think it's a case of waiting for a course for a particular unit. And I've heard that once the smaller units are filled, any future recruitment would mean going to Sellafield. If that is the case, the possibility of a transfer would be slim as the other units should be full. But in the world of the CNC anything can change at the drop of a hat.