Welcome onboard Karl!
As Glenderg says about the attic - leave the stuff in the floor as it is, just put boards down over it, and then insulate inbetween the roof joists. This is the road I'm going down with my attic. I got a secondhand Styra (as seen on the Late Late Show!) from Donedeal for €150, and I have started putting chipboard flooring down, sitting on 4" joists. I'll insulate inbetween the roof joists when the flooring is done, as it can be rightly chilly in the attic at the moment!