If you go DPS Medic, you'll suffer in the healing department. However if you go full healer/buff Medic, it will be extremely hard to kill you, and you will be very sought after.
Even going full healer in QB I will still able to do decently in PvE since I had one or two combat skills handy. Also, I can honestly say that I really didn't have a problem with running out of SP (MP) all that often. It was moreso the longer cooldowns in the beginning on the combat skills that affected me.
Something to note: you can use your healing skill while you're moving (just not while on your bike)