Technically, people seek out Trisquel as an alternative to Ubuntu or Lubuntu
in your case. It is a niche distribution that you go into knowing that many
creature comforts of the past like Flash or proprietary drivers will not
work.
Think of it as a distribution that forces you to behave yourself and be more
cautious in the programs you install and what is actually going on behind the
scenes. It also reminds you that the software on the system can be run and
studied without restrictions.
With your Flash problem, you can try an alternative like Gnash or Lightspark.
If you do seek out the Flash player from the Canonical Partners repository or
bundled with Google Chrome, you are using software that doesn't fit well with
the distribution.
If your point is to install a free distro and load it up with non-free
software, then just install Lubuntu and forget about Trisquel.
