damn dude. shitty.
My experience when my car was totaled was that they gave me MORE than I thought it was worth. So I wouldn't stress too much on that.
It gave me enough for a fat down payment on a brand new car. I could've just bought another used one straight out though.
You should call his insurance company to ask about the coverage on a rental. They should be able to help you. Your insurance company has nothing to do with this since it was all his fault (unless you have full coverage).