Leveling; build for survivability?

[Sinaloa]

You can get as much VIT as you wish, a healer can't tank a lv50 instance. Don't think about tanking, think about healing.

or if Scholar dpsing.

But if you had to tank every Boss the chances are very good the aggroproblem is not tankrelated. If you are just spamming Medica the tank cant do much about it unless he is quite overgeared.