I agree that WoM should be core, or at least that you can cast the turret while moving.
I'm not concerned about tactics I mean the 3 from tinkerer are great, same happens with coordinate strike, FC, MA, Hollow points even Tangling Wire can be used, there are a lot of good tactics for eng.
What I would do is something fancy with Phosporous Shells and Sticky Bomb. Keep the weak long dot but change the second part to "if it is removed increase your CD by 5 secs" or "if it is removed deals a high amount of damage to the one that remove the hex". Something different from the typical heal debuff or things like that, then the healers will have to think if its worth to remove the dots or not (imagine a dok receiving damage from 6 dots that shouldnt be removed...) obviously it should be mirror to the magus.
Another skill that need some love is strafing run. It is instant, but the delay since the animation start until the plane arrives is annoying.
Just to finish, I think that all the skills from the grenadier tree should be casted while moving (You are throwing grenades, it is easier than aim with a bow, you can do that while moving

).
So we would have 3 quite different ways to play the class. A short range tree, a long and static but with high dmg tree and a medium range tree but with high movility.
I really enjoy my rifleman/grenadier engi, but the class will need some love once T4 arrive.