Bingo! There would be absolutely no reason for it to have "streamers" of gas coming off it, no matter how fast it was going through the vacuum of space.
2) (Just guessing here) The trajectory should probably be in the same plane as the rest of the galaxy.
Nah -- it could have gotten flung off in any direction with respect to the plane of the galaxy.
Having nothing else to do, I was just thinking about what would happen if an entire galaxy was flung by a black hole and slammed into another galaxy, and remembered a thread about colliding galaxies a year or so ago. It had a picture, too (hope they were standing a safe distance away).
So now I'm wondering: When two galaxies collide, do they make a loud noise?
Gore said that the streamers are from the melting polar caps due to the natives screwing up their planet with global warming. That it is their own fault that they are being outcast from the galaxy 'cause they continued to drive their SUV's.