is it possible/probable for a prospect to exceed his projected ratings?

Projected is just an estimate. Estimates can be wrong.

possible yes, probable - certainly not. You will find that many more prospects don't reach projections that exceed them. A rule of thumb is usually projections tend to over-estimate a players potential rather than under-estimate it.

Also the less time a player has spent in the league the more sway in numbers. After a guy has spent four or five seasons in the league chances are his numbers aren't going to greatly increase.

I think that projections can be low. We just tend to not notice. Also, projections can never be below current ratings, so there's nowhere to go but up!

TheJester74 is absolutely correct - unless you have very little budgeted to ADV scouting. In that case, it's possible to see lots of prospects reach and exceed projections because the projections are not always higher than reality (or potential).

I've yet to see a guy exceed his projections when I've had $20M in ADV scouting for his first 3 years of pro experience; conversely, now that I have a team with very little in ADV scouting, I'm seeing guys exceed their projections regularly.

That all said, projected ratings are for suckers. If you can't see major league potential in his current ratings, the player more than likely will end up what he appears to be - not good.