>I read somewhere that every package is a vunreability. Should this principle
be applied to home/office workstations?
Yes, who not?
>The problem is not about *installing* useless applications but about
*running* useless applications. Especially those interacting with the
Internet.
Running internet apps can be exploited by a remote attacker but a local
adversary can exploit installed apps as well.
If you don't use something, get rid of it. Saves you disk space, useless
updates of packages you don't even use, might give Trisquel a better idea
what packages people actually use and then there is this security angle.