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
I have arch and plasma 6.
My doubts would be the dual booting with windows. Maybe go with grub for the boot.
From what I've seen on the news Nvidia cards are getting much better drivers these days, it depends on the age of the card, newer cards will not perform well, the drivers are always behind because Nvidia won't release the code so everything is retro engineered. Still better than 3 or more years ago. The Protondb page can help with some games but if the game is deck verified, most likely it plays on Linux.
Don't wait, there's never a perfect time on Linux, it's always evolving and getting better.
To daily drive, expect things to fail, but with plasma 6 I'm sure you'll have everything working out of the box and it'll be a breeze.
Have a look at this.
https://pine64eu.com/product/pinetime-smartwatch-sealed/
You can see the specs and get the idea of what you might need
I use it on my home server, TUI only, when I want to organise my files