I like to use https://yewtu.be as landing page, because it has been around for long with no down time and it has an easy name to remember.

My experience is that using any Invidious instance in combination with yt-dlp on the command line makes downloads already work. Just saying.

Good questions.

Thanks

I really like https://github.com/Swordfish90/cool-retro-term but usually I use xfce4-terminal or gnome-terminal.

Security hardened : https://archlinux.org/packages/extra/x86_64/linux-hardened/

For watching YouTube without ads, besides the already mentioned Newpipe, Piped, and Invidious there is also FreeTube app which can be configured to use Tor proxy.