I think that's a super cool idea, and I hope it gets implemented! My idea, for a more short term solution, if it's not technically impossible with the engine: What about some flags to skip some of the physics calculations on various parts (gravity, drag, collision, etc), or maybe just a flag to pass things up to the parent object it is connected to?? That way you could still have all the little frilly parts you want, for looks, without destroying your ability to play? Maybe this would only be used by non-stock parts, but it seems like a useful thing to have available, and doesn't sound incredibly hard to implement.
