Thanks for all the replies.
One thing I am worried about if I go with Operative, will I be forced to heal during Ops or is the class good enough to DPS? Also does SWTOR have a feature like WOW where you can switch your talent trees on the fly?
Good enough, yes.
However, dps operatives are, of the advanced classes, probably the worst one to take into an operation. Just about all melee specs either do more sustained damage, have gap closers or take damage better (usually all 3). And all ranged take less damage being out of harm's way more often while still doing slightly more damage most of the time.
While I've been in hardmode operations with dps operatives (rarely), I don't remember wiping because of one.
Still, if you go dps on an operative, and there were a "draft" so to speak, to decide who gets to go to an operation based on usefulness, you would be picked dead last.
Healing, on the other hand, for a minority of fights (usually things that require a lot of movement; in more stationary fights, sorcs do the best) and every pvp map other than huttball, operatives are the optimal choice for healers.