Don't understand your question / problem. Why couldn't a FTL ship reflect light / be visible - after it has slowed down to manoever in the Earth's atmosphere?
E=mc².
So what?
Regards,
I think because a ship that reflects light is made up ultimately of atoms. Atoms moving faster than light would seem an impossibility in that the signals between the nucleus and surrounding electrons would result in those atoms being torn apart.
E=mc².