I also had concerns about that as well. My thoughts were, well... either you treat the bloodline like LA all the time(Which means no advancing max skills, advancing caster levels, or anything else a bloodline level would normally do. It is LA.)(Probably frontloaded from the perspective of buyoff. Treat a minor is 1 LA, moderate 2, Major 3), or you treat it like a bloodline(So advance max skills, advance caster level, but no buyoff). That avoids the issue of them being used to qualify for a class, then removed. It also removes the ability to pay some XP for a CL boost.