copy and paste comes down to X11... Xquartz version is MUCH better than Apple's X11, even though Apple uses Xquartz builds to make their X11... it just isn't kept updated. Remember as well, no matter what X11 your using, that you use CMD+c and CMD+v for shortcut keys in OSX, but you have to use Ctrl+c and ctrl+v over in the windows program. If you really want to make complete app ports, I'd really suggest using Wineskin instead, as that is the main goal of it... yes I'm a bit biased since its my project... but you shouldn't have to worry about X11 issues or anything else since its all built in.
