The quick & dirty method to project is to assume that "high" is about 23; "med" about 12; and low about 3. If you used scouting reports, then you can identify between 5 categories of potential improvement. There are many forum strings that point it out, but "Massive", "Tremendous", "Sky's the limit", & "Significantly" indicate categories that can be projected to about 30 points of improvement. [I'll let you look elsewhere in the fora for the precise potential ranges.]
The most important bit of advice is about O & D IQ. You're running flex & man. IMHO, man defense requires good DE ratings even in D3. That makes Wilson somewhat marginal even with the "high" in ATH and Lovejoy a liability on the defensive end. It is not easy to switch defense and I would never advise switching offense (change teams instead). You'll probably do better by standing pat, but make sure you practice IQs, at least at 20 each and possibly up to 25.
The biggest problem your team faces is the lack of a PG. If you're willing to stick it out, then starting Thomas at PG and Brown at SG is the way to go as they will improve quickly with more minutes and starts, but it will be a bit tough while they learn. Brown will be a stud, but for his defense. Lovejoy will probably need to be your backup PG. If you do start 2 freshman, then go ahead and start Howe as well. In your 4th season, this team will be very strong, but not so much this season.
Finally, if you've already purchased an additional season, then hold a couple freshmen out of the first exhibition game and try to give them a redshirt. If either Frye or Bien has big upside, then you could give them a shirt. I wouldn't bother with Wilson as that 84 WE will make it easy to max out his ratings anyhow.