My two cents: don't take Ceramic Plating and Rebraced armor until you get to 30-ish or so. You're better off maxing out the damage talents first like Steely Resolve (9% more aim) and Overcharged Cell Capacitator (6% more from elemental attacks) in your pre-30 levels. I admit, at early levels energy management can be quite tedious at times. But trust me, the more levels you pick up, the more fun talents will unlock: free Explosive Surges, free pulse Cannon and Energy Blast which is not on global cooldown, does a little damage and recharges some cells for you. Honesty, sometimes I don't know what to do with my energy ;-) Do this in dps gear you pick up along the way and you're questing just as fast as most others. As for a rotation, try not to overuse Explosive Surge or Ion Pulse. These babies can starve your energy quite quick. The more levels you get, the more you will get a feel for either hitting Hammer Shot one more time or hitting an ability that costs and could put you into a lower energy regen.

There you go, you just solved your own problem by stating the most important rule of all: play what you like! So unless you're able to create a sith bounty hunter or operative, I'm guessing the inquisitor would fit you best. Every, and I mean EVERY class can perform a certain role at endgame.