For the most part I agree. But I think height and especially weight should change a lot more in the game than they actually do.
Speed does progress some in NCAA 09. I recruited a 4-star power HB, he came in with 82 speed. Now as a true senior he has 86 speed. That is pretty realistic I think. But it doesn't seem to happen with a lot of players.
Here are the rough guidelines that I think should govern speed progression:
1. It should progress faster for higher-caliber players. So if you want to recruit a 2-star 90 speed player over a 4-star 87 speed player, go ahead, but the 4-star is likely to pretty much catch up to him toward the end of their careers.
2. It should progress faster for slower players. If you start with a 50 speed prospect, he should progress maybe 2-10 points of speed during his career. If it's a 95 speed prospect, he probably should only improve 1-3 points of speed during his career.
3. In conjunction with #2, position should affect the speed gain. So an 86 speed 4-star CB should see his speed progress faster than an 86 speed 4-star LB. Thus if you recruit an 80 speed HB prospect and then move him to FB, his speed won't progress much if at all. (But maybe his strength will progress faster.)