Do you think the narrator was a good brother to doodle?
The narrator, the older brother of Doodle who is thinking back on his childhood memories of his relatively short time him, pushed his brother beyond the frail boy's limits. However, he loved him very much, as evidenced throughout the story. Keep in mind that these are children; even the older brother was only a pre-teen and still a selfish creature. So, the narrator helped and pushed Doodle, spent time with him, loved him and packed more action into Doodle's brief life than he ever would have seen had he been left sitting on a couch, waiting to die and not given a chance to really live. In that respect, he was a good brother. Should a child be resposible for not realizing that his younger brother is not just trying to outrun a rainstorm, but actually fighting for his life and in way over his head? That's a subjective question. It is up to you to decide if the way Doodle died, and any responsibility the narrator has in his death, cancels out the years of friendship he demonstrated (albeit bittersweet at times as he regretted Doodle's limitations.)
That depends. The question asks what do you think. There is no right or wrong response.
Look at the story from beginning to end. Perhaps the character starts off not being a good brother (ignoring Doodle etc.) and then gradually changes (by teaching him to walk) and becomes a good brother. Does the ending of the story suggest that the narrator's intentions in helping Doodle were for Doodle or for himself?