Just a meaningless picture of wires, no idea where they are from and to. You need to show what cables are connected to what. The master socket is where the external cable enters the house.
That’s exactly what it is to me. The wire highlighted in orange is the master wire that enters the house from the telephone line.
That is just a junction box where external cable is joined to internal cable so is the socket wrppedwith the cable your master so let to which extensions are connected
Yes I think the one wrapped with cable is actually the master socket and it’s the one we want to remove, is that possible?
No
As I posted everything to master socket is property of openreach