I always do persuasion, it can save you credits and open up conversation options not available even with Force Persuade.
My "needed" skills are Persuade, Repair, Computer, and Awareness - anything else I can usually find someone else to do, though a Sentinel could have plenty of space for Treat Injury and something else too. (I always take a little security and demolitions too, at least for getting goodies from Peragus.)