Looks good, the texture makes a nice outline, as Prophet said, they are a bit simplistic atm, but that's not really a problem, as long as the lines are clean and it looks effective, that's what is important.
It sounds to me like you are using Modelview to add the thrusters, which doesn't work properly for it. I always use Pof Constructor Suite to add the thrusters at 0.0 (and remember to set the diameter of them to something other than 0 else they won't show then either), then use Modelview to move them around, since modelview can adjust existing thrusters.