I wonder if someone can clarify this. Say in a brexit situation we decided the best course of action would to join the EFTA countries? Obviously free movement applies. Would we however be free to use our own laws for the deportation of criminals without being overruled, or to stipulate how long immigrants can be here looking for work ala Cameron's deal?
If we enter EFTA the free movement rules would be as they are now, but without the tweaks that Cameron got in his re-negotiation. Depending on the exact arrangement we make we might, or might not, be subject to the European Court of Justice but, if we're not, and we behave contrary to the EU rules then the EU would consider us in breach of our treaty and respond appropriately.
Also, most of the times I'm aware of that deportation has been overruled it has been by the ECHR not the ECJ, and we would remain party to that.