Thanks again @jem101! I'm getting clearer, though still confused on a few details.
If I could ask a few more questions please...
I've just now emailed the original electricians (they didn't give us the dodgy advice, just wired the house following the plans), I suggested we add 2 ethernet sockets alongside each current VM socket. I'm *hoping* there might be a way to run Cat 6 cable through the same ducting... I'll see what they say.
Each coax cable currently runs to the same point, coming out in our hallway (where we also have our electric meter, etc). There are 6 of them, cos we have 6 Virgin sockets/holes around the house. They all come out near the front wall where our Virgin line comes in from the street.
I can't get my head round what those coax cables will connect to though? Is that the hub? Or something the engineers will fit (is that the brown box you see on the outside of new builds)?
We have 6 Virgin sockets/holes, so if we added 2x ethernet sockets next to each of those we'd need 12 ethernet connections to the hub? If so, we're definitely going to need a 16 port gigabit PoE switch.
The ethernet cable would all come out in the same place as the VM coax, I reckon. So the gigabit switch would also need to be there? And we'd also put our VM hub in that same place too, if we had something else handling routing?
We currently have a couple of Netgear Orbi mesh network devices that have handled routing/wifi in our previous non-Virgin houses. I just turn off wifi on the ISP's supplied router and let the Orbi handle it instead. It's usually better coverage and signal across the house.
Will that set up work with Virgin's hub? If so, I'd just put the VM hub along with everything else in the hallway (cos no need for it to be in a central location for better wifi coverage)?
And also, would it work with the switch? Would the VM hub connect to the switch and then connect the main/master Orbi router to the switch also (not the hub)?
I don't know if I could also manage ceiling mounted wireless access points wired to the switch, cos it's already going to be a huge pain retrofitting the ethernet sockets at those VM wall points. Maybe the wifi mesh network would be acceptable? It's not a huge house. I was looking into https://eero.com the other day as an alternative.
Once again, huge thanks for your time and patience with all my questions. I wish I'd have asked these questions before the house was planned and built, instead of blindly accepting what I was told. Hindsight is wonderful eh?! 🙂