I run this in a Docker container on my home network without connecting it to their cloud platform (despite their - increasingly strident, it feels - “encouragements” to do so). It’s very powerful, and the majority of low level configuration is done via text files. But 99% of it is automatic.
The UI is unique. It’s a single, long and scrollable page, which may be an issue for some.
There are other tools out there, too. I previously used one that integrates Grafana, Prometheus and Node Exporter, which is more complex to set up and configure.
Yep, with the desktop versions of Signal, Matrix (Element) and Steam chat.
I’m yet to try out gamemode, which may help. But I typically close Signal and Element when I’m gaming, so it’s usually not an issue for me.
Edit: I’m on EndeavourOS, KDE, i7, 16GB, Nvidia 2060.