Desktop shortcuts: just delete.
whonixcheck should show if networking is down. Probably the bug where upgrade of whonix-firewall breaks networking.
fix fail closed mechanism
telnet is a dependency of https://github.com/Whonix/tor-ctrl. The protocol is no longer recommended for remote connections but fine for use in local network. The package installed by itself does not cause any security risk. telnet does not run itself.
Not convinced, I haven’t seen any rar file for ages and no users asking about it ever.
No. Debian default. See:
About showing DOS/Windows: ignore this level of sometimes non-nonsensical output. Too much expected perfection. Unrealistic. See:
Will get back to the other items later.