I strongly encourage you to dive with Mark M. It is in those times that he will be able to observe you and offer suggestions as to your continued improvement.

As for the "re-do", each instructor may be different, but the apparent norm is this. If a provisional is given, then one attempt is a "free be", after that each attempt will cost the student. If an outright failure is given then the student must pay all class fees when re-taking the class.

You would do well to seek out other DIR divers to dive with, because they will be your best source of information and input. It is in this enviroment, that you will start to see and appreciate the DIR philosophy and their adherence to a specific gear configuration. Stick with it!!!! The end result will be well worth the effort.