If his contract is like others, he would be required to pursue a position to help offset the buyout. Not that he gets hired, mind you ... only that he consider all potential offers and make a serious effort to pursue.
Paul Finebaum explained how the "coach parking" works. An agent (in this case, Jimmy Sexton) takes one of his failed clients and parks them at a school with a good name/reputation. After 3-4 years, the sting wears off and he can re-sign the coach to a new contract at a more attractive price. While it's not stated that the coach who agrees to manage the parking makes a cut, Finebaum suggested that by saying, "They aren't doing this because they are nice guys." A good example is Butch Jones being parked at Alabama.
Unfortunately, his contract isn't like (most) others. Our contract with CGC included no offset clause for future employment or earnings. So in the unlikely case that someone decides to pay him $1M/yr to work for them, he keeps all of that...and the buyout money that GT continues to pay.
There's no requirement to look for work - anything he does moving forward is 100% of his own accord. (Or his wife, I suppose, if she wants him out of the house.)
Agreed with your other thoughts re: him not returning to coaching.