This is a super cool concept. I wish there was a downloadable version to skip the lag I have on browser. As it is, this is a great customizer. I do agree with the idea of a template shape (even if it doesn't appear in the final render) to help us drawing challenged folk. I also think that the term "front" is a bit misleading for the engine. Maybe say "thrust direction ->". Not sure if it's just me though, but in my mind it's engine faces backwards to push ship forward.
That being said, this is super impressive. The drawing functionality, and different layers for different items, I can't even begin to understand how this works. 10/10 very impressive