Without going into it in any great detail (that has been done many times and you can actually get all the information from the GUE website), the "skills" are how to handle task loading without losing buoyancy, trim or your teammates (buddies).I guess my question is threefold.
1. What are the skills that are learned in DIR-F?
IF you believe (as I do) that maintaining buoyancy, trim and team awareness while task loaded is important, then no, there isn't a subset of skills. (Note, the actual skills you learn, air shares (S-drills), SMB deployment, valve drills in reality are more for task loading than the acts themselves -- although the acts ARE safety related -- but the non-silting kicks are good in and of themselves.) In photography, to "Do It Right" you need to be able to maintain your position without losing your teammates AND without damaging the environment (although I do know a certain photog who maintains that the environment is secondary to the shot!) -- and that means being very good at maintaining buoyancy and "appropriate trim" (which may be upside down) while getting the shot and knowing where the team is (which is a lot of task loading).2. Is there a subset of those skills that would be appropriate for photography?
Whatever it takes for you to be satisfied -- if the Card is not important.3. What level of proficiency is really required?
As to whether there is some other class that teaches these skills either for photographers OR for recreational divers, I only know of Breakthrough Diving's Essentials -- which is "DIR-F" in workshop form. My cave instructor asked, "Doesn't PADI's "Peak Perfomance Buoyancy" teach this?" I could only smile.