1. I have seen a ball python become confused or reluctant regarding live prey after it's become used to dead prey, so I'd suggest picking something and sticking to it. If you want to go with dead but can't always get it, you can pre-kill the prey for your snake.

2. For the amount you'd pay for a wild caught or captive hatched ball python from Petco, you can have a nice normal captive bred one shipped to you by a known breeder. It's worth it to do that instead and significantly reduce your likelihood of parasites and increase your odds of a good feeder.