1) Does HLDJ launch the game correctly for you? Yes it does.
2) Does "HLDJ Loaded Successfully" appear in console on starting the game (with no errors)? Yes it does.
3) What is the console output after selecting a song, or issuing other HLDJ commands such as "hldj_next"? Host_WriteConfiguration: Wrote cfg/hldj_cmd_b.cfg
Loaded : worst od
When I do "hldj_next" I get Loaded: yes Host_WriteConfiguration: Wrote cfg/hldj_cmd_c.cfg
4) Create your own local server and set the appropriate sv_ commands (see above), then: I don't understand what to do here, how do I create a local server?
5) Does voice normally work for you? If not, or you do not have a microphone, have you remembered to set up any applicable options in your operating system and/or the game? The noise happening in the video actually happens when I try to talk, although it only happens after I'm done speaking.