The ACC "rights" issue is really a self-solving problem. If Clemson, FSU, VA Tech and Maimi leave TV isn't going to pay the ACC. If one team left that wouldn't be the case. One team will not announce a defection. It's going to be group decision by necessity. If you're the SEC it's a question of leverage. If the ACC football schools are not in the SEC then the SEC be dividing the pie. The SEC can gain control of the football crazy south in one fell swoop. That's the obvious move IMHO.
Anybody can sue anyone for anything. I would doubt an individual school would have standing to sue (guess). Once the football schools leave the ACC will no longer exist with the interest to sue. There will surely be suits and there will surely be settlements.