Mythic. After you tax a city, you may place 1 resource you have over the planet's resource icon. From now on, its planet type is the placed resource, and its planet type cannot be changed again with Mythic.
Ancient. You cannot Catapult move from starports, but you can Catapult move from gates.
A: Yes, you can use resources from a Cartel card for Mythic.
A: Yes. The ability just indicates that you cannot Catapult move by using the starport.