Okay, so my empire can pretty much do whatever it wants now.
I found a fun way to test my ship designs. Whenever one of the majors declares war on a minor race, I give them one of my dreadnoughts and watch while the major sends fleet after fleet to their destruction. Some minor races will immediately send their new gift to their homewolrd (which is disappointing), while others leave it in place and apparently can't move it. Its more fun when they can't move it because I'll park the ship next to the major's homeworld right before handoff and sit back and enjoy the show.