1) Does HLDJ launch the game correctly for you?
Yes.
2) Does "HLDJ Loaded Successfully" appear in console on starting the game (with no errors)?
Nothing HLDJ related appears at all.
3) What is the console output after selecting a song, or issuing other HLDJ commands such as "hldj_next"?"maxplayers set to 24
Steam config directory: c:\program files (x86)\steam\steamapps\dolphin147\team fortress 2\platform\config
Unknown command "cl_thirdperson"
Can't use cheat cvar cam_snapto in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_ideallag in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_idealdelta in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_idealyaw in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_idealpitch in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_idealdist in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_idealdistright in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_idealdistup in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar cam_collision in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_maxpitch in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_minpitch in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_maxyaw in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_minyaw in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_maxdistance in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_mindistance in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_orthowidth in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar c_orthoheight in multiplayer, unless the server has sv_cheats set to 1.
Unknown command "sv_backspeed"
Not playing a local game.
GC sent new item schema; updating
Can't use cheat cvar fog_start in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar fog_end in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar fog_startskybox in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar fog_endskybox in multiplayer, unless the server has sv_cheats set to 1.
Can't use cheat cvar r_farz in multiplayer, unless the server has sv_cheats set to 1."
Unknown command "la", etc.