I just wanted to reply to the video card problem.
Yes, indeed, this works as stated!!! -- Super easy setup. literally 4 clicks. Awesome!
Regarding the second thing. When you say a portjail -- What is then the difference between a regular jail and a portjail ? so I would have to say: ssh -X firstname.lastname@example.org
s and then start the applications via command line that I want to use with X11.
In any case thank you so much for your help. I really can't be happier with my installation right now.
PS: should I delete the applications I already installed and installed them via portjail?