When you use a crappy engine it doesnt matter what year you are in. If you ever played ilum when people actually went there youll see this game can not support large scale battle.
Roll an operative. They have been OP since release healing wise. Insta cast with many stuns on short cooldowns and utility. I would say Roll Sorc, but Sorc is getting nerfed again. Operatives will continue to be OP healing spec'd.
Full madness isnt that bad if you know how to kite which you will be doing 100% of the time against melee letting your DoTs do the work. The only reason I cant win against a assassin 1v1 is because of their immunity to force attacks so I have to eat the 2k or so force lightning not able to attack or stun them.