I always enjoy posts like these. That said, Franks is a RFR. Other RFR QBs in UF history include Bell, Grossman etc. At any position if a RFR with no one in front of him is not ready to play, then you must wonder if he ever will be. Some do develop late, but in general you know what you have with a RFR. (Dobbs was a true Soph close to the same thing as a RFR when he showed improvement.
Technically, McElwain has already competed for championships at UF and is starting his 3rd season. Him getting to 7, sorry SD, seasons is not hard to imagine so that statement is not so encouraging to me.
As for Callaway, he could be following a common path. He established he is an NFL talent as a FR. He coasted a bit as a Soph. It is his money year so I would not be surprised for him to have as big a year as possible given the UF QB situation in this his money year.