Clipping a flighted CAG negatively impacts their psyche. Flying also helps keep their cardiovascular system healthy.
All birds love to land on 'perches' that are high up. There's not a whole lot you can do about it except to put something on top of it that may prevent her from landing there while she's out.
All 13 of my birds, which include 3 CAGS, are flighted and not one of my birds has ever plucked.