I thought the same but is the spark asking as he doesn't agree with what's being requested....
Don't take this the wrong way OP but either do it now properly or not at all. Running cables and not doing anything with them is a bad idea IMO. The type of questions you have asked make me feel you don't fully understand what's needed or how to go about it - that's not a dig just an observation, you can't know everything about everything
I think he believes one port in each room will be enough and I don't think it will be in years to come or even now it's not enough.
I will be running what ever cables from each room back to under stairs where broadband is.
Your right I don't 100% understand what's needed but what I do know is that I should be running cables from where I can back to the router. I will be having ports near any thing electrical (TV,computer etc)
What I meant by leaving the cable, is I won't be purchasing any equipment just yet. So just getting all the cable Into the walls and out under the stairs should be enough for no (I hope). I will then at a later stage buy a cabinet and patch panel and switch so everything can be connected up.