The engineer is complex and will take time to get used to. In the spirit of understanding that profession better, I'd like to know how you played it, and/or are planning to play it.
When I played it, I aimed for a more healer role, mixing healing and dps. It'll need some tweaks but it seemed to work well. I liked being able to switch to healing when needed (though with cooldowns you can't heal 100% of the time) while being able to dish out damage without risking running out of energy.
I have not tried engineer in PvP though. I'd be curious to learn what works there.