If you're talking about on Sylverant specifically, you can certainly do so, as long as you register the serial number/access key on the Sylverant website. You'll have the same guild card and everything else that way. Only one can be online at a time though.
I'd imagine the same is true on other servers, but I can't speak for them.
APrip is a portable open source tool capable of bypassing/patching-out the ‘standardized’ additional anti-piracy copy protection found in some later...