Based on my experiences with public transportation, I think a 30-A/Sowal system would be hard to make work just because of how spread out things are/the hot weather.
I absolutely LOVE public transportation ........... until I need groceries, have to wait in the heat, or walk along a road w/o a sidewalk to continue to my destination.
A seasonal shuttle from tourist hubs would be a more realistic/funn way to move people around, but I don't know if most people would utilize them beyond drunk taxis, bored teenagers, and special events.
If there was a 30-A shuttle I'd definitely use it to go from Seagrove to events in Rosemary, Grayton, Alys Beach, Redfish Village, Blue Mountain, Gulf Place, Watercolor, Sandestin etc. but I am not the typical user/driver, as I drive less than 10K a year and prefer to ride/bike rather than drive at any opportunity.