Looking at the general plans for the new terminal, the building itself would not affect any existing building as it would be located between the existing Eastern Perimeter road and Twy A, on what is currently grass. However, it looks as if the new terminal is very much on the back burner now anyway.
As far as the train station is concerned, that seems to be located immediately North of the existing ADS Aerial/Corporation hangar (sorry, showing my age there) so should not impinge on the flying club areas unless the B52 club is tight up against the railway (to where the platform might extend)at the very southernmost part of the flying club buildings.
No doubt detailed plans will be forthcoming at some point.