It can. For instance I have a flake where I define all of my machines, share some confit between them and have clearly defined customisation points.

Form that configuration I can build everything on one of my machines and push the builds to the others. Or each machine can do its own builds.

Have a look at projects like NixOps or Colmena to see some more automation on top of standard builds targeting other machines.

Depending on your specific requirements, yes. And quite elegantly.

There are several ways to do this. For one, see: https://github.com/nix-community/colmena