you get it in veilstone city some galatic guy in front of the sattelite will drop a pokeball
Yes, if you have a key duplicator or a small file and time. But almost any hardware store can cut keys for you for the purchase of a key, even if it says "do not duplicate".
In Yen or WOWgold? NI-HAO!
Beat the 7th gym leader go to veilstone and go to the HQ and talk to the grunt and he drops the key