Boxers are one of the best family dogs! I have 2 right now and no children. We have lots of extended family with small children that we only see a couple of times a year. My youngest dog is like the Energizer Bunny on crack, but she is so gentle when she is around little ones it is an amazing transformation. Both of my dogs think kids are the best thing ever and adjust to a child's level of play.
Depends on how you train them. Boxers are very strong dogs and if you train the wrong way they will end up seriously hurting people but train them the right way they will be flipping on to their backs to complete strangers.
I don't know about best but they're generally very good natured and tolerant around kids. The first dog I remember paying with when I was a kid was a Boxer. He was my buddy. I don't remember his real name but I called him Smiley because he always looked like he was smiling.
In a way, dogs are like people.....alot depends on your upbringing and environment....there are good ones and bad.....they can change with time....and could turn on you in an instant and leave you wondering how it could happen. Most dogs are great with children by instinct.....but you should still have the dog trained in basic obedience just the same. If you want a 100% guarantee that the dog will never, ever harm anyone....then don't get a dog....or any wild animal ( yes....our 'pets' are still wild animals no matter what we want to believe ) because there is no such guarantee. Not saying your pet will ever be anything but a loving companion for a long time....just telling a truth that some choose to ignore.