is it ok to "sudo update && upgrade"? or should i leave Tails version the way it is to avoid any anwanted compatibility changes or anything else?

thx

No. This is not supported and may break Tails security properties in awful ways. Don't do this unless you've read and understood all of design, and are happy to take responsibility if you shoot yourself in the foot.
Comment by Tails Thu 06 Jun 2013 08:12:26 PM CEST