You should be able to switch classes whenever you want just by changing the tool you're using, but to be fair I haven't tried any of the non-combat classes yet and not much has been said about them in the first place.
His Excellency Aethien wrote:
If no one debated with me, then I wouldn't post here anymore.
Take the hint guys, please take the hint.
I'm not getting my news from anywhere Joph.