Options:

• Just start it from the terminal with torsocks
• Use application-specific proxy settings
• Since torsocks simply uses LD_PRELOAD, you could try to make this apply globally by adding the torsocks library to ld.so.preload. Just put the path returned by torsocks show in /etc/ld.so.preload.

Either use the --proxy option of yt-dlp, or use torsocks to transparently torify any application.

singlelogin.re still worked for me recently.

Source

We have those on I2P already, see tracker2.postman.i2p for example.

You should not torrent over the tor network, but you can torrent over the I2P network. qBittorrent even has experimental I2P support built in.