WoW didn't have a built in meter for years, but that didn't mean that threat was never of a concern in game play. It always was. Hell I remember raiding back in MC and being told not to do anything until 5 sunders were up on every mob. Ironically, it seems that once Blizzard did make threat a non-concern by making AOE tanking vastly easier than it ever has been, that is when they finally added an in game threat indicator lol. TOR absolutely needs something in that form whether it be through an in game tool or an addon because tanking is a pain in the ass right now with being completely unable to tell where people are on threat and who the hell mobs are targeting without spamming my get target's target hotkey.
My only comment to the OP is about this. Are you quitting or staying because you seem to waffle back and for with every post/thread you make. Truth be told, I figured you would have quit about a month ago when you made that other thread complaining about the UI saying it was game breaking for you.

Everything else is opinions and you are more than welcome to have them, especially since you stated them in a constructive manner, and you are damn right about the AH interface being terrible.