Back Pocket, with your vacuum points, check to make sure they're using the right plans, and that the plans don't have massive "dots" where the points should be. If they do, then they might just be following (incorrect) instructions. Putting a vacuum point in can require a bit of adjustment to suit the frame, but putting it into a different room isn't acceptable. As for how they fix it now plaster is up, not your problem.
Personally I don't like ducted vacuums. I had it in my last house and while it never broke down it seemed less effective than my Roomba.
Thanks Lurgen, in a previous house we ended up with vaccuum upstairs and another one downstairs so went with the ducted. In reality there were only one set of ducting plans, I never sighted or signed any others. I am chasing my BC over this at the moment. Our SS is on holidays for two weeks and we will be requesting a meeting when he gets back to go through quite a few things.
So glad to hear that things are getting sorted and you are happy in your new home!