Some questions about my phone/adsl setup

[joe384]

Hi,

I moved into a new build last year, when I moved in there was no BT/Openreach line, and there were 2 white telephone cables unconnected going to a socket in the lounge and one in the bedroom. I had a line installed and I got openreach to put the master socket (5C) close to the cables so I could wire up the extensions if needed. I have since changed to the faceplate to the filtered one.

I was looking at the socket in the lounge this weekend, and noticed it is a "master" socket (it has the capacitor etc on it) and the bedroom one is a "secondary" (no components)

So I now have the following questions:

1. Why is the socket in the lounge a master socket? Did the electrician assume BT were going to connect the incoming line via a junction box to the 2 cables (without installing a NTE 5c)
2. If I wanted to connect the lounge socket, do I need to change it for a "secondary" type socket
3. If I connect an extension to the NTE 5c master socket (voice terminals), could any interference on the extension wiring affect the broadband signal at the NTE socket? (Reason is I know the cable for the lounge socket runs alongside most of the mains wiring)
4. Same as no 3 but for a broadband extension instead of voice, if I wire up a broadband extension to the user-side A/B could any interference (even if nothing was plugged in) cause interference at the NTE socket? I guess even without anything plugged into the extension (just the wiring connected) something could still induce a signal into the wiring