I haven't a clue how to begin coding that so it would come up properly, how exactly would assign racial spell casting after the race has been chosen. And as for the Custom abilities, I wouldn't want to simply overwrite them..
How would a cleric choose domains, or a wizard select specialized schools, for some classes it isn't an issue. But it is for many, and since we are adding class abilities, we are also limited to how we can use them.
Not to mention the difficulties with class abilities and feats that run off of class abilities. For the base class that's easy, but for the variation we are adding.
Rogue/Sorc variant class: and then they wanted to go. Woodland rogue, since we have to use the Sorcerer as a base class, the variants that affect the rogue would no longer be applicable.
whole mess of messiness.
And alot of fun to try and do, which is why I've played around with it.