That is not ENTIRELY accurate. The ratings are still based off of the numbers and distribution for ratings in Madden. The only difference is that hard data is used for raw attributes and scouting data is used to calculate subjective information. So, it is not like you will have QBs only having a maximum of 80 THP or something like that via FBG, rather, the THP is calculated using more accurate information outside of the strict opinion of a software developer.
As for classes, that is not being considered at this time, but a colleague is working on a site to use FBG for NCAA Football gaming.