1. It's a little bit later than usual but I don't think it's ever "too late" and a lot of people actually recommend waiting as long as you can to let all the growth plates close.
2. No, neutering does not change a dogs personality. It could make them a little calmer, less aggressive, stop or prevent marking habits, prevent unwanted pregnancies, most unaltered males WILL find a way to get to a female in heat, they can smell it from miles away. I believe 80% of dogs hit by cars are unaltered males, so it can cause less running away.
3. Jackson was back to 100% normal on day 3. By day 2 though, he was feeling nearly all better.
