1. I've already answered this.
2. Drivers who go straight on a left only lane > 1 long horn. Why should I care, it's none of my business.
3. Drivers who cuts up everyone in a queue at a traffic light by driving down the wrong side > 1 horn. Why should I care, it's none of my business.
4. On a 3 lane dual carriageway, if I am on the right lane, and I am driving at the speed limit, if someone flashes me > Ignore and continue. On a motorway, if I do happen to find myself on the right lane, I will try to move to the middle lane as soon as it is safe to do so. Why does it make a difference whether you're on a three lane dual carriageway or a motorway? I think you need to educate yourself on the correct way to drive in roads with more than one lane.
5. In a roundabout, if the car next to me is partially driving in my lane or about to drive in to me > 1 long horn. Finally we partially agree with something. If someone is about to drive into me, whether on a roundabout or not, I'll tap my horn. That's what it's there for, it's to warn another user of my presence.
6. At a mini roundabout, if a car does not wait at the giveway line or drives in while I am going round > 1 long horn. If they're not encroaching on my space or about to hit me, I'll just ignore them.
7. Meet and greet situation in a residential road where it is a two-way road and cars are parked on both sides > If I am near the end of the road, I will reverse. If I am in the middle of the road or towards the front section of the road, I refuse to reverse all the way down the road , tell the other guy to reverse and switch off my engine. I've never been in this situation where someone has refused to make space. Would you actually get out of your car and tell the other person to reverse or would you sit there, making yourself look small and wait for them to reverse? It all depends on who has a space closest, it's called common courtesy.
8. If someone is driving at night with no headlights, use full beam and a long and loud horn. If they're coming towards me, I'd probably give them a very quick flash and then forget about it. I certainly wouldn't use my horn.
9. If someone is driving without headlights on a motorway, get in front of them and flash hazards a few times. If I'm overtaking them, I'd go pass and continue on my way as normal. If they've overtaken me, I'd continue on my way as normal.
10. If on a motorway, there is traffic on the left and slow traffic in the middle lane but no one is in the right lane, and I move to the right lane and floor it. One of the daydreamers in the middle lane sees me and then comes behind me on the right lane and flashes me to move out of the way > Ignore him and keep going until I have gone past the slow traffic in the middle lane and can go back to the middle lane. Sounds about right.
11. On a motorway, if someone comes in front of me at a car's length without indicating > 1 quick horn. If I'm not in any immediate danger, I'd just back off. Yes, the other person isn't driving particularly well but if they're not about to hit me, I don't really care.
12. On a dual carriageway, if someone comes in front regardless of distance > 1 horn. You do love your horn. Why would I care if someone moves in front of me?
13. Anyone who jumps a red light > 1long horn. Why should I care, it's none of my business.
How do you remember all these things to do? Do you have a post-it note on your dashboard that you can consult? "Oh, someone's driving at night with no headlights, I should flash them and sound a long and loud horn".