

You can create a virtual machine, running within your debian install, to serve as your router. It actually works very well.
I used a headless Debian VM as a router with Shorewall to configure iptables. If I had to do it again, I probably would have used an opensense VM.
Yes. The relevant metric:
99.55% of posts are on a single instance. That is not “federated” in any meaningful sense.