As usual I have one annoying clue left. I have the 9 unclued entries, the film, the star and the co-star, but what on earth is 28 ac 'endlessly obsessive gossip'?(3). I have A?A, but can't make anything fit!
Finished this clever, if at times frustrating, puzzle. However, I cannot parse 4d (British are ready outside fortress). Probably staring me in the face.