Hi Angelo,
Regarding volume level, you can have a look here:
You may find solution there.
Regarding remote access/administration, have a look here:
https://springsignage.freshdesk.com/support/solutions/articles/3000036699
you can use SSHelper to some degree, same with Shell commands (mostly to reboot and check status)
Other than that some customers are using VNC. TeamViewer or WebKey you may want to look into that.