Engineers don't put up a very good fight by themselves. Luckily we have healing and makes it somewhat possible, but still, I only use 5 skills.

Empathy (6)
Revive (1)
Protection (1)
Transference (6) *best skill by the way, so far*
Pain (6)

I should put one into Supression though, it's a good skill for mob control. But overall, it's not a very fun class, compared to say, the Enchantress.

Feel free to discuss. This is just my opinion(you can agree/disagree), and I am aware that there will probably be a rebalance. But for now, Engineer is strictly best as a support role.