Could be marking it or just because it smells So Good!

Socialize him. The more he sees that people are different the easier it will be to accept this. When I was in obedience school, we were told to go sit on a bench on the boardwalk and just people watch. Dog gets used to different people, smells and you are there for "comfort". Go to dog parks, dogs are pack animals and will act like the other playful pups. Most of the time I take dogs in car to store. I walk dog a short distance. I go shopping. We then walk a short distance. If dog was abused all you can do it be very calm and consistent. I have a "noise" I make when dog doesn't do the right thing (like going to the cat box). This immediately stops them. When they walk away I say in a high pitch voice "good dog" or something positive.

NO! Dogs try to digest these non-food items and it can cause digestive problems. Bones from the butcher or feed store, vet-recommended digestible things are the way to go.

Your dog sounds bored. More playtime, get another dog to play with, for anxiety leave a special item of clothing with pitbull, and talk to her/him! Calm and consistent.

When dog pulls, immediately reverse direction. This means a lot of turning around, but the dog should start paying attention to you and not anything else. Calm and consistent.

Get him a playpal/another dog. They play with each other and not you. Playpal another dog/gerbil whatever. Another body helps.

Try leaving something with your scent on it with him when you leave and tell him exactly what's going on. They will listen to your positive tone and feel better.