The script will never work, its designed for RaspiOS. You have to read the script and then perform the actions the piCore way.
I hope your not going to put a display on your pi that is playing audio. That is going to make audiophiles start twitching.
Of course not, it will be on another pi. I keep things as light as possible on the pi device that is playing audio. I'll come back ASAP here too, with a tutorial for making one of the the smallest and best audiophile sounding network player on the market based on piCore, a rpi device and other key hardware devices. All of them has made possible a true high-end network audio player who rivals best-in-class audiophile network players.
Btw, audiophiles may start anything they want, I'm one of them