Drk opener as mt

[Chronons]

N E V E R pull with Plunge or use Unmend>Plunge under any circumstances ever

I think this is an interesting point, and for the sake of my own understanding i'd like to push back just a bit. Front loading potency while you are in Grit means two things: you get to get out of Grit faster, you reduce the probability that you have to go back into Grit.
You regard plunge as a potency loss for the melee dps as they must use their gap closers or sacrifice a sec or two to catch up, but do not address that plunge is an asset to DRK for holding enmity with ranged dps. You better believe as soon as you use Unmend your BLM is going to go ham. Plunge helps keep you ahead of the ranged dps in enmity. If they have to wait for you to run the rest of the way to the target that is a one or two second dps loss for them.
Your rotation has one Power Slash Combo. There is no way that is going to hold hate with any kind of competent dps. Ever since 3.2 changes it takes at least 2-3 before you should consider dropping Grit. If you have to go back into Grit or use a Power Slash combo after dropping Grit the first time its a huge dps loss. Much more than using Plunge on the pull. In principle I think you are spot on, save potency for when it is not going to be debuffed. However, experience tells me to do that you will be saving plunge for far longer than one PS combo.