Hi! I've worked with erpnext previously so I can help you without problem writing manual for install it
Just be advice abiut enviromment, you need to use the same linux version and dame distribution too when you need install in other server.
1) We wish for you to install ERPNext ([login to view URL]) on our server. However, it will be installed on a production server so it is VERY important that ERPNext does not break other server processes.
Is totally possible.
2) We know that ERPNext uses MariaDB out of the box. Can this be changed for MySQL? If not, we must either run MariaDB on a different port OR install ERPNext in a Docker environment
Yes, erpnext can uses mysql without problem. I've set up with mysql server previously
Jus a question, what linux distribution are you using