I agree with some of the general sentiments that rockstarfozzy gave: most of the time, trying to evaluate a "broken" thing in D&D is kinda pointless. In my opinion, "broken" means "challenges the DM in new ways." Personally, I enjoy being challenged as a DM, so I don't mind having a player try something that others might consider "broken." To me, it's more of a test of my ability as a DM to roll with it, and make sure that in the end, it gets balanced - and that everyone has fun. (At the end of the day, I've had far more problems with specific player personalities impeding fun than with any game mechanic I've ever read.)
Even the infamous Book of Exalted Deeds can be contained by a DM willing to work with their players and be careful about how the power is used.