Virex

I currently have Threaded Steel Ring, Immortal Brigade Ring and Band of Thuuga.

For MT'ing which would be better to pair with the Treaded Steal Ring? Is 6 aggression going to accumulate as much threat as 2 crit and 75 CA damage?

Chumann

No. The aggression skill only increases the likelyhood that your taunts will land. It has no affect on how well you generate hate otherwise. If you ask me, +agression is probably the least important applied bonus out there.