I think you all are overanalyzing this. When it comes to groups, any DPS class is going to be wanted. The fact that you may have more of one class than another just goes to show what people are willing to level or what they find fun. I've pulled threat already being a Lancer at level 20 from caster classes. TP is a resource, and proper rotation means you'll be able to manage it far more efficiently instead of burning through it and starving yourself. I've yet to run out of TP except for when I applied Sprint to catch up to my group once due to a single K.O. from the lack of tank awareness.

None the less, I'm going to be leveling all of the classes and roles. I can assure you I will learn to play each and every one, but as it stands... parsing should be able to tell your DPS, but even at that... it's not like one class is going to trump another unless they do some changes that destabilize the balance that all classes have already.