Question three : your best riding
This is quite the loaded question. I mean, if you think about it, everyday that you ride should be your new 'best riding' since no matter how much you know, you should always be improving.
The only exception that comes to mind is people that took a break from riding and are now trying to regain their previous confidence. I had a friend that grew up riding and rode for years, and then took about 20 years off, and when she returned she had zero confidence, and it has taken her time to rebuild that.
I will say that I went to a gymkhana this summer, and I was riding this little halflinger gelding. He's one of my favorite horses ever, he's such a cute guy. He had two riders that day, and he gave us both exactly what he knew we needed. He gave me a speed I have never been before. I think that was definitely some of my best riding.
However, now I am riding pony, and she has given me a whole other level of riding. She is the most oddly sensitive horse you will ever meet. She forces you to use your body correctly, or else she will let you know that there's a problem. She's so funny.