Perhaps hire companies adjusting the expectations of where you can get to from their base, instead of presenting hirers with possible routes/rings that are only achievable at full chat in a week?
I think those who stare ahead feel they have once been slighted by a fast passing boat and have decided they'll now do the same in revenge, they won't acknowledge you as they plainly know they're being naughty. My gripe with those that pass with music blaring, is that it usually happens at some time after midnight, and they're usually pumping out some sort of Belgian hoover music rather than anything good
I'll always slow to pass boats, how else can you gain the time to properly neb through their windows???
To me a more recent phenomenon is the close pass. Moored up on a plenty wide enough bit on a calm flat day, all light through your windows is suddenly blocked out by a boat passing you with a six inch gap between your hulls for no good reason. Perhaps a knock-on from ever shallower canals?