Are these ships allowed to fly with the rebels or the imperials or are they exclusive to their own faction and therefore not allowed to be included in rebel or imperial fleets?

They're their own faction. But for a casual game, you could come up with a scenario that could see them as an ally. When they become tournament legal, they'll be on their own.

They're their own faction. So you can't use them with Rebel or Imperial lists.

Now for a friendly casual game you can do whatever you want, but you may find things are quite broken that way.

Dude, were you looking over my shoulder just now?

Dude, were you looking over my shoulder just now?

I was just thinking that... even had the same time stamp.