I'm actually trying to figure this out myself.Does anyone know how to teach Double-Edge, Quickattack, and Close Combat to Pinsir? I can't seem to find the information.
Double-Edge
The last time Pinsir learned Double-edge was through a move tutor in Firered/Leafgreen back in Generation III, and then traded forward through two generations. As of yet, we don't have the ability to trade forward to X/Y, meaning Double-Edge is impossible for now.
Close Combat / Quick Attack
Close Combat and Quick Attack seem incompatible on the same set; both are Egg Moves, but Close Combat is only able to be learned by Pinsir through breeding with Heracross, which cannot learn Quick Attack by any means. Pinsir also learns Close Combat in the Dream World, but that means that Quick Attack, being an Egg Move, is not compatible. You can have one or the other, but not both. (Not yet, anyway; I haven't finished research.)