I guess that you only see the tip of the iceberg in these "darknet forums". They probably favor visibility for the end-user instead of security, due to their target audience. XMPP and GPG is pretty popular on DNMs.
You could share your compose file.
Can you exec into the qBittorrent container to ensure internet connectivity works? For example attempt to ping 9.9.9.9 or curl duckduckgo.org.
If it doesn't work, try the same from the gluetun container directly.
If it doesn't work from the gluetun container, there likely is an issue with the Wireguard configuration.
I do not know, but I would imagine Telegram needs to release a different APK with additional restrictions on Google Play in order to comply. Otherwise, google would simply take it down.
It does detect the output is being piped though, and defaults to the -1 option in this case, which means print only filenames, one per line. The only issue would be filenames containing newline characters.
If I understand correctly, root means that they are authoritative. They are effectively independent of the classical root DNS servers and provide custom top level domains (TLDs) such as .geek which are not available in the regular DNS system.
Non root DNS servers merely relay requests to root servers or other DNS servers and cache response records according to their time to live (TTL).
I guess that they genuinely owned subscriptions for popular paywalled sites.