Please note that indeed, your current wi-fi card will not work in Trisquel.
The intel card will require non-free firmware, which Ubuntu comes shipped
with.
The best two options you have are to either get a new internal wi-fi card
(Atheros-based), or a USB wi-fi adapter from ThinkPenguin @
http://libre.thinkpenguin.com.
I know it sounds pointless since you already have a wi-fi card, but it's what
has to be done if you want wi-fi on a fully free system. I had to do the same
with my laptop, an Alienware M11x, which came with a Broadcom-based wi-fi
card which had the same situation, requiring non-free firmware. Atheros
doesn't have the problem of non-free firmware. Another issue might be that
the BIOS won't let you switch out the wi-fi cards due to vendor lock-out.
Also, if you like Ubuntu's default interface (Unity), it doesn't come
preinstalled by default. Instead, Trisquel uses a standard desktop layout
running on GNOME 3. You can reinstall Unity if you wish, however, since it's
in Trisquel's repositories.
Other than those two problems, it looks like the T430 should be okay for
everything else, including 3D acceleration.
