Punt #1, Miami (FL): punt returner clearly points with both hands (no waving that I can tell), not a valid or invalid signal. Ball is live.
Punt #2, North Texas: punt returner begins to bring arms up but stops short of his shoulders. Invalid signal as it doesn't meet the requirements of a fair catch. Evidenced by the defense pulling up and stopping. Ball is dead.
Punt #3, Boston College: punt returner clearly points with both hand (see punt #1). Ball is live.
Punt #4, Mississippi State: unclear to me, he looks like he is pointing, but his arms are shoulder height pointing straight and not down. Could be called either way.
Punt #5, UCLA: punt returner arms are up, maybe waving but not pointing. Invalid catch signal. Ball is dead.
Punt #6, Indiana: I see nothing to indicate a valid or invalid catch signal. Ball is live.
Punt #7, South Alabama: Arms go up in a general waving motion, but not a valid signal so invalid catch signal. Ball is dead.
Granted I can't see the entire play most of the time. But according to O'Dey's explanation "It's legal to point, but any waving of the hands is considered an invalid signal." In my estimation 3 of the 7 punts there was no invalid catch signal. Pointing is fine. The rules explicitly state the "get away" sign is invalid. That's both arms conveying 'I'm giving this ball up and letting it bounce.' You can argue that's what Cooper was doing.