There is no Sky City in Pokemon.
In Pokemon PLatinum there r in pewter city
In Hearthome City.
you could only get shaymin sky forme in Pokemon platnium in floromona town.
I don't think so, sorry.
canalave city or the trophy garden.
beat snowpoint gym
use your map to find out
Rock Climb is on your way to Snowpoint City.
You get it in route 204 south of eterna city.
In eterna city Pokemon center the talk to the lady in the pink shirt
get the event shaymin then receive the gracidea flowers from the girl in Florama Town
You don't you talk to Bebe in Harthome City the house next to the Pokemon center