Couldn't they have solved the balance issues entirely by making it so that only a certain set of iconic BLU abilities are allowed in endgame content, and in order to participate in any level-cap DF content, the BLU has to have all of those set abilities? Then BLU could learn all the enemy skills they want for solo play, but still be balanced like a normal class for DF. Especially if job quests specifically send the BLUs out to farm certain enemies for their skills, the feeling of "acquiring all skills from enemies" would still be present, even if there are limits on what skills can be used in endgame content.

This... isn't that hard to figure out, SE...