If I buy some credd and decide I don't wanna play that server can I sell those credds on a different server with a new character?

Or are they locked into that faction and server?

Cross server/faction, but not cross continent.

You can buy one on exile on one server, make a character on another server dominion and sell it and have platinum.

Cool deal, thanks for the info. =) So I simply just can't jump to the EU servers or something, but that's the only limitation?

I'm pretty sure your account is locked to one continent, which is the only limiting factor preventing that.