I am not shure how the rolling versus stable release model fits to Trisquel,
since the distrib is based on Ubuntu, which is stable.
I have been using various rolling release distros for quite some time
(arch64, aptosid, Sabayon) and never run into severe issues. As everything in
live rolling versus stable release models have advantages and disadvantages.
For average Joe user and stable daily use without the need for the latest
bleeding edge stuff I would suggest a very stable distro such as Debian 6. If
you are a more skilled user, like to get the lastest stuff but are willing to
tinker / work out possible issues, then a rolling release is for you.
Keep in mind that even regular updates for a stable distro can break your
system pretty similar to a rolling release. Stable release models do not
automatically imply a more stable usage than rolling release models do.
As for breaking a USB / flash-based medias I still have not managed my 16GB
Sandisk USB stick which previously stored Trisquel and now hosts arch. We had
a lengthy discussion here in the mailing list on this topic. Search and judge
yourself.
As for filesystems I am a bit conservative and stick either to ext3 or ext4.
For now I would not touch butrfs, reiser or XFS for example.
