A couple of questions regarding running ADoom in AmiBench

[SkulleateR]

Does the music actually work in ADoom on the A600GS, and if so, how exactly do I configure it?

You have to use a new version of doomsound.library -> https://aminet.net/package/game/shoot/DoomSndLibs

That one inside the ADoom LHA does not work anymore

//EDIT : oh, and of course you have to start it with "ADoom -music" after putting the lib in it´s place ...

[SkulleateR]

Does anyone have a list of what the ASCII key values are or can point me to a website that shows this?

This one is difficult, you will need the ASCII Key scan codes in decimal values ... but even if you refer to something like https://www.torsten-horn.de/techdocs/ascii.htm the codes for the normal keys like WASD is ok but the values for the cursor keys are not those in the list ...

I found a little workaround, just download https://aminet.net/package/game/shoot/DoomAttack-AIO and use the DoomAttackPrefs program to set your keys, save it and copy the created .DOOMRC over to the ADoom dir

But be sure to NOT do this in AmiBench since DoomAttackPrefs will crash on saving

[SkulleateR]

If anyone can get it to work, please tell me exactly what you did, step by step, as I would love to know if anyone can get the music to work (and how).

Well it works for me and I did exactly what you did 

You can try to delete the doomsound.library in your ADoom dir and put the V38 inside there too if that makes any difference ...

These are the packs I used :
https://aminet.net/package/game/shoot/ADoom-1.4
https://aminet.net/package/game/shoot/DoomSndLibs
https://aminet.net/package/game/shoot/ADoom_Instr