I am now giving more thumbs up than I am having close passes. I dont know if this is just a winter thing, but the driving in the past 2 months has really improved. Either that or I am not bothered by it anymore.
Sir, I imagine you will find things that bother you again in due course. Give it time. Every leopard I've ever seen has had very similar spots to the ones it had previously. Actually, I'm not sure I've ever seen the same leopard twice and there are several I haven't even seen once, but I was making a wider point. All that deleted Youtube footage and one or two recent posts tell a different story about whether various things (road behaviour, nationality, non-matching shoe laces or similar) bother certain members of CC.
On an unconnected point, my wife, a niece and a nephew (and their parents) are Welsh. My father-in-law was Welsh and learned English only to go to school. These are people you might want to loathe, in line with your truthful opinion of them. My children, however, are half-Welsh and therefore half-poor, half-rude and half ill-mannered. You would (I am sure) half-loathe them. Quite right too. Better than they deserve.
Back on topic: As to hand gestures, I find it a good thing to thank other road users and I use something not unlike the salute an officer in a vehicle might give when returning a salute from a sentry: Right hand raised, upright, open and palm forward, elbow tucked in and the side of the index finger brushing the outer end of the right eyebrow.
It looks polite, cannot be confused for anything else and is clear in meaning. It's also easy to do on a bicycle at any speed.