It depends really, as I haven’t read the whole story.
But here’s some answers.
A . Main, I believe that he is the main character because it seems that he has more screen time
B. A minor character, it seems that Sam is the a main character and the gardener is someone who is supporting the him and the story.
Hope it helps.
I'd say adverb. I don't think it would be verb because of the way it's used in the sentence.
................................c
