For baclup purposes I would recommend Borg backup for the tech savvy or Duplicati for the basic user, as they are vastly superior (keeping multiple copies of your files, smart retention, deduplication). Backup gets smaller than source more often than not, even if you have a year’s worth of historical versions. That said, rsync is great for what it is.

A coffee mug!

Cool poster!

Catwoman

Kubernetes is too much. You could set up a matrix server for chat with jitsi for video meetings. Use element as client. Then add your game server(s).

For matrix/jitsi server setup use this playbook https://github.com/spantaleev/matrix-docker-ansible-deploy

It installs all you need for video, audio, and text chat.

Maybe change the config to be unfederated if you want a private server.

100% uptime is really not feasible so forget that. Even the commercial servers have downtimes.