Proxmox maps user ids between itself and lxc containers and it took me a bit of time to figure it out. I would highly suggest reading the following link as it's how I worked it out. I ended up chown'ing to 101000 which maps to user 1000 - the default user - in my lxcs.
https://www.itsembedded.com/sysadmin/proxmox_bind_unprivileged_lxc/
Leave Kodi behind in 2010 and switch over to Jellyfin for better results.
This is exactly why for everything fediverse, I only run my own.
Is River City Girls 2 any better than the first game, which I thought was okay but seemed a bit unresponsive in terms of control?
Not having a problem with this on my personal instance yet, but I've had to disable DASH because it takes forever to watch anything when it's on these days.
Games back then took 20 people. Now, upwards of 2000 for modern AAA games. It's nowhere near the same.
Your logic works if you assume that we are making games at the same scale and the same way we were 15-20 years ago.
The one and only thing keeping me on Chrome... well, Ungoogled Chromium... is the webassembly performance which is just abysmal in comparison on Firefox, sadly.
By the way, running synapse - docker or not - is a challenge. It can be very complex especially if you are interested in adding gateways to other services and such. Attempting to use https://github.com/spantaleev/matrix-docker-ansible-deploy might be a better choice as even though it is A LOT, it has a ton of good documentation and you can grow with it as it can help you install various different Matrix servers, gateways and clients as well.
Good luck, hope to hear more about how you get on with it.
It took a little time to get the hang of it, but stick with it and it will get so much easier and it'll make self-hosting anything you want less of a pain in the future.
As it says in the image, the file is /data/homeserver.yaml. Your other questions are all answered by looking at the way the file is formatted.
There are dedicated Jellyfin clients but I mainly just use the web client that is part of the server 90% of the time.