Congrats on your new scaly friend! We're looking forward to seeing photos whenever you can post them.
1. Yes- switch her over to f/t as soon as you can. Feeding f/t is safer for your snake, since a live mouse can cause harm to your snake (scratching, fighting back, etc). Give her at least 7-10 days without bothering her at all (unless to change her water dish or spot clean) to give her time to settle in and get used to new sights, smells, and surroundings. After those 7-10 days, offer her a f/t rat appropriate for her size. Warm it up really well. Use tongs and make the f/t rat "dance" to appear like a live rat to entice her feeding response. Hopefully she switches over without much fuss. If she misses this first feeding, don't worry. She might just need more time to adjust to her new home.
2. Your humidity is WAY too low. You need to have humidity at 60% at the least, and up to 80% when she's in shed. Ball pythons need good humidity levels to avoid respiratory infections and bad sheds.
3. Your hot side is too hot. You should have the hot side be closer to 90F, and the cooler side around 80-85F. How are you heating the enclosure? Is it an under tank heating pad? If so, you MUST have it on a thermostat. The thermostat will measure and maintain the temperature of the heat pad at a desirable temperature (without a thermostat, most heat pads can easily go up to 130F or more, and this can burn your snake's belly).
Try to get us photos of your set up and we'll try to help you out where it's necessary. We want to make sure you have the right tools to keep your new friend happy and healthy. Good luck! Keep us posted and don't hesitate to ask any more questions

. The ball python section of this forum also has a lot of helpful threads with vast amounts of information.