[Feanor...]

I agree, I don't like the depiction of balrogs as hulking beasts. However I disagree w. Kuruharan's statement about balrogs losing the ability to change shape. Remember Balrogs were once Ainu and the ability to change shape was native to them in the begining and the only reason why Melkor and Sauron were no longer able to do so was because they suffered such grevious injuries to their person that they could not easily change their form with out much pain and effort. For example when Morgoth was attacked by Unguoilant he was very much injured as we see from what happened to the land of Lammoth. And Sauron's ability to take a fair shape was lost when he got caught in the downfall of Numenor. In each instance they went through massive injury. However there is no indication that the balrog endured the same type of ordeal. Besides the fack that he fled the War of Wrath but the very fact that he escaped is more strongly indicative that he was able to escape Manwe's fury, thus escaping injury.