It is a fork of Spring engine, called Recoil, so yes.

https://en.wikipedia.org/wiki/Thorn_(letter)

Depends what you are looking for. If you enjoyed capital warfare, no. They are expensive now. If you like big tidi fests, sure. What were you doing/enjoying back then?

Frontier is not Vanguard. Frontier is a blockchain based survival game (whatever that actually means), Vanguard is the FPS extraction shooter.

Same, if you do find it let me know please :)

If you rebind the pause/unpause button, Starsector can be played mouse only too.