The next two questions....
3. How did you improve so quickly as a beginner?
Basically, I believed in myself! I always tried my best, never gave up, and of course, I truly enjoyed playing the game.
4. Who was your first coach? Did formal training help you?
My first professional coach was Goran Milicevic, probably when I was in grade 3. He is an amazing instructor, and I would recommend him to any student. He helped me learn an assortment of tactics and strategy, but most of all, he gave me unconditional support, and I can't thank him enough.
As for other training, I've read some books on my own, and attended Chess 'n Math after-school programs and camps. All were very helpful.