Police spotting (junction watch)

Okay, I'll write down what I would do in situation that you've described;

1 - If someone did a punishment pass while I'm in primary, I'd brake hard while moving a little into secondary till the vehicle is now in front of me, and resumed back into primary.

2 - If someone tailgating, I'd look back, acknowledge them and carry on riding till they think there's enough room to overtake, and if they did 1, I'll repeat what I did with 1.

3 - Horn blaring, verbal abuse etc. this is usually one of the situation where I'd just pull over and let them go, no point in confronting someone with a big broad sword against your garlic crusher.

4 - Very very rare, people just don't suddenly do this for no reason, they did when I confronted them back when I didn't had cycle training let alone experience, but nowadays it's rare as hen's teeth, if I did 3, then 4 is even less of a likelihood.

Without knowing the conditions on the ground, those default avoidance tactics are meaningless, Ed. They might be appropriate or they might not. Traffic and road conditions are dynamic and the circumstances of each incident are going to be different. However, you are at least addressing the point I made about the need to prepare and take action if confronted with a road user who takes umbrage at your central lane position.