Answer: yes, i think so but can differ in different situations. But generally, then yes? ( still my opinion )
I can tell you the first one is " last year I could sing very well" not sure about the others I'm so sorry ( maybe its right )
Answer: It is a part of the rising action that shows a conflict between the dogs.
Explanation: Usually in a pack of dogs, there will be a fight for dominance. Spitz intruded Buck’s nest to show him that he was top dog, which would have been seen as a challenge to Buck, and it shows a battle will follow soon.
The last sentence about reliving the writers younger days as in memories