Okay,
So you are basicly dealing with the same mechanics as I do.
Depending on where the Dread is being tanked ( one tank or two ) I try to time out ID On Avatar ( ofc after the fresh HT and Phl ) as the Dread is popping and starting to move. I tend to move directly through him three or four steps ( depends on what angle you tank Avatar ) turn and apply Dis, Chaos, Phl, drop Dragonfire on them both, go into a rotation until I see new Homing Missile come out, I rotate it out of group position swapping to Avatar, reapply Chaos combo to Avatar and normally pop Mercy Stroke on the Dread to kill it.
This should be able to be done on any but the first Dread since you will have the CD of Dragonfire up.


Pots, I use on every pull. First time seeing it, through a kill and farming. IMHO it is part of Raiding, and a consumable. Even if you are swapping to mega pots of progression learn phases. It helps keep your timing in your rotations down, since you will be using them come kill. Until on farm , you should be going through two to three pots every pull. Later, probably two.