Yes, you can heal and do well as a commando. However, if you were a sage/sorc you would be doing much better.
The lack of utility is my biggest gripe. That and how freaking weak hammer shot heal is. It is almost not even worth using it because all it does is put a huge bull's eye on you. It leaves much to be desired.
The main upside I see is that I rarely ran out of ammo unless I am trying to put out some damage. You stay above 50% ammo and you regen a good bit of the cost during the cast. Then again, I have no idea how resources are for other healers.
I would love hammer shot heal made more appealing and useful. Perhaps hide the beam to enemies, but visible so that your team sees it. I love the graphic of a beam healing and really want it to be more.
Not crazy about Kolto being an aoe targeted heal. I see it's value, but I would rather have it work like a grenade. Better yet, both. Not like there are a lot of choices for heals.
Oh ya, an interrupt would be great. That or a ranged snare, or better, both.