nfsm

I also pay for it and watch it on my android TV. And I completely agree with you. But for now it's my main source of TV and I mainly follow channels I subscribe. I don't listen to music on YT, i do follow some live music channels

Thank you for the write up. It's very helpful.
I'd pick another CPU (even Intel) but I understand that you're bound to the motherboard. I'm looking for a SFF build, what's your PC-case?

I also couldn't get sddm to work from the KDE settings. I changed the sddm.conf file manually and I'm using the catpuccin theme. The Arch wiki helped (as usual).

Yeah, but the form factor of the steam deck makes it more appealing if I want to set It up in the living room

Ok. I get it now. I've been trying to build something cheap as a Linux gaming setup and I've come to the conclusion that I'm better off buying the steam deck.

Warning

If a user executes the Reset this PC command (Settings -> Update & Security -> Recovery) with the Keep my files option (or the Remove Everything option) the Windows Restricted Traffic Limited Functionality Baseline settings will need to be re-applied in order to re-restrict the device. Egress traffic may occur prior to the re-application of the Restricted Traffic Limited Functionality Baseline settings. To restrict a device effectively (first time or subsequently), it is recommended to apply the Restricted Traffic Limited Functionality Baseline settings package in offline mode. During update or upgrade of Windows, egress traffic may occur.

This guide just helped me realize why I don't use windows. The fact that you need to remove and not add is why I like Linux.

I would stick with SMB and SSH(SFTP). SMB for content sharing and accessible on any device like PCs or phones. SSH, which includes SFTP, for accessing everything else on the server.

+1 for bazzite. And OP had already worked with fedora

Fedora atomic (I'm using bazzite for gaming only) have Flatpaks enabled by default and are recommended, so it integrates well with the OS.
And seeing where the Linux community is going right now, Flatpak has been widely adopted by most distros which are not Debian based. There are ways to go regarding the packaging for the developers, but there are plenty of apps already on flathub. I'm using it on arch and bazzite and have no problems so far.
I can't comment on the apps the OP requires

Security starts first with you. Most of the attacks are done though social engineering. Email phishing, dodgy webpage logins. Normal password security behaviour should fine for you to use the pc. More importantly, what is the distro you're using? Maybe consider using Flatpaks for the apps, they tend to offer more restrictions on access to the system. (Installing the torrent app as a Flatpak and only give it permissions to a specific folder) One of things I tend to do is install chromium just to login on my Google apps, Gmail, YT. But I'm more of a non data sharing freak.

I haven't noticed any issues. But only Plasma would be a DE. Qtile and hyprland are WM, not sure if that makes the difference.
Initially I had doubts if it would work, but so far so good.

Nice work. Why move from plasma to hyprland? Install both and login on the environment you want at any time. I have qtile, plasma and hyprland