The reason people pull this way in Gazluk is because many of the monsters can kill you outright with a critical hit unless you are sitting on something stupid like 1k health/armor. Critical hits being bumped up to what they are currently encourage people to subvert the mechanics.
The reality is that if you are in perfect rolled armor in a strong group (with the trinity) then Gazluk should probably be easy to clear and relatively boring.
#3-4 wouldn't be an issue if the monsters had code to detect their primary target was out of range and would immediately spin to something in range (already covered in previously mentioned thread). So that will get fixed in time.
It is quite common in other games like this to see a tank with 60% mitigation. Citan said he doesn't want anything like that but he has crits tuned to a point where that much mitigation on a tank would actually make sense. On the bright side it seems that he decided that crits might be too high (because so many people were bitching about being full hp and then dead).