Here are some pics of my boy, he'll be 5 months in 2 weeks. He's been doing great and has improved amazingly in every single aspect of his behavior. The first 2 pics were taken the night we got him, the last 2 were taken yesterday.
No idea, sometimes with mixes it's so hard to tell what the parentage is. I do think that your dog's head is a bit more refined than many of the pit mixes i've seen.