Yes, there are special situations where you don't want guard on a melee DPS. For example:
- TfB second boss at start where we actually want the best geared melee DPS to "tank" Heirad.
- EC NiM on Trandoshans where we want the best geared melee DPS to "pull" and kill the Trandoshan Warriors away from the rest of the group.
My post is however not directed at the crowd running these operations, but the generally less enlighted crowd on LFG.
Also if a tank is pulling 1000 dps, a DPS will have to pull over 1500 dps to pull aggro due to "high aggro" moves. However assuming you meant tps (threat per second) it is still slightly off, as you haven't included the range modifier to aggro.
Yes you are absolutly correct, I was trying to keep it as simple as possible. All "high threat" abilities have a threat increase of 0.5x. That is, using a tanking stance, a 2.5x modifier on damage to threat. Also the "aggro" doesn't switch targets on a 1:1 threat ratio, but on a 1:1.1 (melee) and 1:1.3 (ranged) threat ratio.