I've been using this Destiny thing to "Cheat" a little bit (Giving my generated rookies a 0 or a 1 after I Draft them. You really have to do it for the actual 2007 drafted rookies, cause EA has their destiny messed up.
something else that I have found is the "learning" rating(The higher the better). I haven't played with it much, but I think it represents how susceptible the player is to training, (they may loose whatever they gain during the season during summer time, though)
There is also a workethic stat, wich I believe is self explanatory. 0 is the best, 2 is normal I think