Hello. I am sorry for all the hassles you have experienced. AmiKit system involves many unofficial patches and other various improvements that makes the old Amiga system modern however old programs might not work correctly with AmiKit. I don't know Music-X but according to the screenshot (the icons) it must be very old. Even plain and real Amiga 1200 was not 100% compatible with old Amiga 600 programs. Since AmiKit is built on A1200 (or A4000) system it is impossible to make it more A600 like.
But you can try to boot into Amiga Forever OS3.1 environment and install the Music-X into it. AmigaForever's OS3.1 is plain and patches free.
Or, even better, if you already have your A600 environment as HDF, simply boot to this environment and install the Music-X into it. But don't forget to configure WinUAE to behave like A600 first. You don't need AmiKit for this at all.
All you need is to:
1) start winuae, configure it like A600
2) attach your HDFs and boot into it
3) insert the Music-X ADFs into virtual drives
4) install Music-X
or alternatively boot from Music-X ADF directly (again with WinUAE configured as A600).
I found some info about WinUAE configuration here http://www.jonnydigital.com/winuae
The kickstarts can be found in Amiga Forever distribution.
Or doesn't Amiga Forever contain the pre-configured A600 config so you could load it up directly?