QClock. Beyond genius level. Beyond anything ever seen on earth before.

Here is a way I can see Q being JFK JR:

If JFK JR actually did die in that plane crash,

went to heaven and learned, was shown everything, saw the whole tapestry, past present future, all the connections, and then was allowed to come back to Earth in his healed body. Retaining all knowledge he was given in heaven.

Only in this miraculous way could he attain the level of mastery, time travel, remote viewing, and all-knowing of Q, who must use several methods to be able to communicate in this wild proven fashion.