My Dog Constantly Rolls On Her Back And Wants Her Belly Rubbed.?

I recently got a 2 year old Papillon mix. My friend adopted her for my birthday knowing i had been ready for and wanting a dog. however when ever you walk up to her or play with her she rolls on er back and just lays there. this gets in the way of training her to learn to stay and sit when all she does is roll on her back and waits for her tummy to be rubbed. now i don’t know if this means anything but this dog was left in an abandoned house when her last family left her lock in a house. she was only found when someone called to complain of a barking dog. She had several rotted teeth and had many pulled and the remaining where deep cleaned. they told my friend she was most likely abused due to how extremely hand shy she is. Now however she is glued to my hip and never leaves me. i was wondering if her rolling on her back could be what she did when she was hit like playing dead? is there anyway i can stop this act?

My Son Wants A Puppy? I Need Help Picking A Breed.?

My son is 6 and we are getting him a puppy. We already have a smaller (35 pounds) female siberian husky, she is 8 years old. He would like a smaller dog, but foremost we need a dog that is very friendly and not aggressive. We’d like a dog that is easy to train and isn’t yippy or doesn’t bark a lot. Any suggestions? I’d like to get a golden retriever, but I know he wants a smaller dog. I’ve also thought about Papillons and elkhounds. Help!