I don't disagree with anything you've said. There was an interesting article in this week's BHW, on sparrowhawks & pergerines, and although I don't agree with everything in that article, especially the figures on losses, a couple of bits on self-help did make sense. And these were changing what we did during their breeding seasons; basically no breeding YBs before March / April (avoid s/hawk) and no racing before end of May (avoid peregrine). Although the article was written by conservation groups they were very candid in their advice if followed would mean we would stop feeding these things, so there would be fewer of them around.
this would only work for a while because like everything in nature the hawks would evolve and change their breeding habits to suit their needs