Breastfeeding on average burns 500 calories a day, with the typical range from 200-600 calories a day.. So yes you'll lose weight much much quicker.. You should google it there are some good articles on the subject..
Everyone is different. Right from delivery if you breastfed it would help your uterus shrink down quicker.
You do burn extra calories when breastfeeding. I still kept on 10lbs almost the whole time I breastfed my son and then when I started weaning him is when I lost it. Same goes for this baby. I'm still up 10lbs but we are only 3 months in. I think it does help in the long run though.
My stomach has gon down a lot in these two weeks and I'm breast feeding.