The only licensing issue was the Steinberg VST-SDK, Ardour doesn’t use the VST-SDK anymore like Seablade said so Ardour is legally free and clear for both Home and Commercial VST usage. The only caveat would be if some particular VST plugin was limited to home use only, which would be the case for any D.A.W. you were using.
As to your other question about importing the song files/folders into a new Ardour install, as long as the original song folders where you kept your project are intact you simply browse to them with your new Ardour install and open them, all of the settings and arrangements will be there. If you have some missing plugins or inserts missing you may get an error saying that Ardour couldn’t find them but usually this is easy to fix.
had the same export problem with ubuntu 9.04 rt kernal n ustudio stuff added on , getting my firewire working etc etc…also ubuntu’s wireless internet works kinda crappy too, and it took me forever too get flash to work right on 64bit…( sorry to rant ) but that export problem is the icing on the cake for me and ubuntu… gmaq im gonna try your special sauce ( avlinux2.o ) hahaha !!!
VST plugins I believe only work if you compile Ardour with the VST=1 flag (Yes you would have to compile it yourself) because VST licensing doesn’t let anyone distribute anything with their implemented code. http://tinyarticle.com