I think that gnash works pretty well with youtube. Not sure, because I have
gnash deactivated. I use the ViewTube greasemonkey script which works
perfectly well. You can also use youtube/html5.
mp3 support comes out of the box. No non-free code is needed (mp3 is to be
avoided for patent reasons; Trisquel is based in Spain where software patents
do not apply if I understand the situation correctly).
Full disk encryption is available through the installer. Last time I tried I
encountered a bug (Ubuntu bug, not specific to Trisquel), where one of my
CPUs would always be at 100% with a full disk encryption setup. You may want
to check if you have this bug on your machine as well.
