Do you get an email from Apple when you purchase something off of the app store or iTunes?
Not right away. Depending on what you buy or rent it takes a few hours to a few days to get an itemized receipt.
Yes, they send you the receipt and the totally spent.
Yes, everytime I've bought something I have gotten an email.
I've always got a email same day
Yes and you can always check your account using iTunes on your computer