yes.. i have 2 boxers and i leave both in my house while i'm at work for 8+ hrs. if you get a young boxer, you will want to crate it first because it will chew up everything if left alone for an extended period of time.
I have a 3 1/2 year old boxer who is and will be for some time in a kennel during the day for 8+ hours. He gets plenty of excercise and while coaxing him out of the comforts of the "human bed" before we leave for work is a chore, I know he sleeps 90% of the time he is in the kennel during the day. I would highly recommend not keeping toys in the kennel with the boxer as they will tend to chew it up. Even the blanket I have in the bottom of the kennel has been ripped to shreads until my boxer gets it just the way he wants.
My boxer was a rescue from a family who's 10 year old son abused my girl. I was nervous about her being around not just babies, but children of all ages. Turn out that she not only loves children still, but is very mindful of her size in relation to children. She can pull me around the house, no problem, when we play tug-o-war, but is very careful and gently when playing with my friend's 3 year old. Obviously, take care with baby in your arms as boxers do love to jump and LOVE to be a part of everything you do, but I think if you got a puppy before the baby was born, and took him/her to obedience classes, you should have no problem when the baby arrives, since the dog will know commands and you can correct any behavior that might be a little too rough around the baby.
no absolutely no
Yes, but if a puppy you need to get someone to let it out at least once. Definitely crate train and rule of thumb is age in months + 1 is how long they can hold it before needing to go out. I am also a teacher and was able to run home at lunch. Luckily they grow fast and by the time they are around 7 months and housebroken will be okay. Remember that most people with dogs have to work and a teacher schedule is probably one of the best to have. You can try to time your pups arrival with your summer break to make it easier, just remember to crate train and try to simulate your schedule somewhat before returning to work so it's not such a sudden change for the dog.