It’s in Germany, but check out https://herzberg-festival.com/en/information/. Pretty much fits your description.

I have used mailinabox.email (I think there is a docker version of it) and am quite happy with it.

I have a .yt domain, because it was cheap and had the three letter domain I wanted… I still dont understand, why that TLD ist more popular with youtubers…

I had problems with soft locks because somehow the PSU was in corrupt state, maybe through a black out or something. The problem persisted through reboots and power offs, only cutting power helped.

TVHeadend, but it has a really steep learning curve.

Mine does a “Look at the huge turd I just dumped in the litterbox!” meow