Well just to jupdate those on my situation, I had everything installed yesterday. All went brilliantly. BT guy turned up first, migrated my phoneline/number. No new phone socket required, brilliant. Sky guy turned up and was excellent. Really friendly and didn't mind me being picky (on behalf of my landlords) about dish placement and tidy cabling etc. Very happy. So thanks to everyone who answered my silly questions, however I do have one more.
Currently with my VM box I get a HDCP 2.2 error if I plug it straight into my amp (VM TiVo -> amplifier -> TV). It's a known issue, so I plug it directly into my TV and route the audio-only via my amplifier. Do I need to do this with the Q box? Does it experience the same issue? Or can I plug straight into the amplifier as per most other devices.
Also, I've downloaded Sky Go and Sky Q apps to my phone. Which is better/what's the difference?