: Gothmog didn't jus command Balrogs though. He commanded many other things as well. He wasn't Captain of the Balrogs he was Captain of the Tower. That would seem to mean that he is capable of commanding things.

Capability doesn't necessitate career. Just because Gothmog and the other Balrogs may have had the ability to command, doesn't mean they wanted to. Perhaps Gothmog needed the extra money, he may have been saving up for a down payment on a new lair!? Aditionally, we are assuming that because Gothmog commanded, that other Balrogs had similar abilities and talents.

:I have to wonder why you think that Balrogs are only useful for fighting? They could also use spellcasting because the one in Moria broke Gandalf's door shutting spell.

No necessarily spellcasting. Gandalf said it was a counterspell, and it could have (though we have little knowledge of the way in which Gandalf's magic worked) just a general spell, or a natural extention of the Balrog itself, something it countered as a reaction rather then a conscious spellcasting. In either case, it seems that a counterspell of the level to thwart Gandalf would be a highly effective weapon in a fight. Certainly the Balrog's abilities ultimately killed Gandalf's mortal form.

-RR