Given your feet/leg issues. You may well be beyond the skill level of most bike fitters. Is there a well respected PT/Bike Fitter in your area?
Perhaps call Eric Moen at CorpreSano PT in Seattle. See if he knows anyone in your area.
My guess is that you can have a positive experience with "clipless" if set up correctly.
Beyond that. After you get the pedals/shoes....Practice against a wall in your house for a while, then go to the park and stop/start on a variety of slopes ON THE GRASS before giving them a go on a quiet road/trail. You want to develop good instincts to clip in/out before you go "out in the real world' No scraped skin that way.