I'm fairly certain that Kiffin, when he left for FAU, was not being looked at by other programs. It was a surprise to everyone he was leaving, particularly for FAU and I know it was a hot topic of discussion as to whether he was helping his career or hurting it by doing so. He's getting paid like 500K or something like that which was a big reduction from his salary of OC at Alabama.
I think his image needed more repair than you suggest. He failed miserably at two high profile schools while having attitude and image issues and then was seen fighting with Saban on the sideline numerous times in their run. He will likely get back into the P-5 ranks at some point but I think FAU was the best he could do at the time. Too bad that wasn't now as we could have potentially had a shot with him just like they did if the timing was better.