I don't have this problem about not finding my main via /setfocus "name" macro.

I've run 1 Pally + 3 Shamans in a group with Crusader Aura from the cave in AV all the way in North Tower that sometimes dip down to 19 fps.

I do however sometimes stop for 2 seconds certain junctions where there are lots of objects such as trees, and change in terrain (going down or up from Icewing).

On long stretches, sometimes one of the shaman's loses the Crusader Aura buff. This is noticeable in AB from the starting gate and running straight to BS. I notice that after I passed the farm, the losing of Crusader Aura happens around there, just before the bridge.