Personally, I'd like to see the whole low/average/high/high-high potential categories done away with as I feel it gives too clear a picture for where a player might finish ratings-wise for the $ expenditure one makes. I can FSS an entire state and have a reasonably good image of what players will look like by their senior seasons...sure the high-highs you have to scout for, but more than once I've foregone that element to save a few bucks because "even if it's only a low-high, 21 points onto that rating will make him solid enough, anything above that is icing on the cake."
I'd like to see it more like Madden (or at least how Madden used to be since it's been a few years since I consoled and may well have changed by now) where you get a range for each attribute...Player A's Ath 35-75, Spd 55-95, Reb 1-15, etc....FSS would obviously narrow the ranges for the players in the state more than the baseline and subsequent scout trips would pinch those ranges in tighter to the actual attribute cap, getting rid of the annoying I-sent-my-scout-on-eight-trips-and-never-got-a-speed-report situation. If you really want to be creative, you can have something where you assign points to your scout...maybe you want him focusing more on Ath and Def, so assign more points there so the range in those attributes pinches a bit more on a single trip than it does for, say, shot blocking.
I've also thought it would be fun to have the HD equivalent of HBD's "diamonds in the rough" where you come into a season and potentially get a random email from your assistant coach "Wow, <Player X> must have really worked on their game over the summer. I saw him playing a pickup game in the gym and he looks like a totally different player." and then you'd discover said player's caps in random categories have been bumped up a handful of points.