Some Questions About A New Ball Python

i do not know if this will make any difference, but i noticed a little difference in the way our snakes take their f/t mice based of the temp. if it was too cool nobody wants it. we just put em back in the ziploc and run them under warm water for a while longer to get them to what would be normal temperature for a live one and boom they take it..good luck

It sounde like you are the kind of person we need in this hobby; someone who is not afraid to do research, and not just an impulsive buyer who wants to hold that new snake the day they get it. :)
I wonder; were they feeding the snake live, or prekilled, at the pet store? Many snakes that are used to eating live, will ignore even prekilled mice.
I admire you for taking in those unwanted animals. I have found myself doing that too; our cat was basically one of those "old owner takes him for a car drive and opens the door" cases. Our horse was bound for the meat auction when we got her; she was actually a registered Paint, but her former owners ran off with her papers, so she is basically worthless to anyone who breeds, and we got her for a quarter of the cost she was worth. It feels good to save them, doesn't it? :)