The Amish who need to see a doctor go to regular doctors. Most Amish schools only go up through 8th grade. Higher learning is discouraged. There are very few Amish who become doctors. If they do, they would leave the Amish and attend regular universities like other medical students. There is no special program just for Amish.
They don't. Since its against their religion to use any electricity, and that's what a lot of it is today, they use old methods, or adapt from new ones.
I've actually go to Amish Pennsylvania quite often. There are some medical schools in the area. It's not all farm, cows, and manure. They have grocery stores and churches and restaurants just like us.
The Hippocratic Oath encourages those who get their MD to go where the need is great and devote their life to helping people with their health, so I'll bet a lot of them Amish doctors are regular people who don the Amish look just to make sure people are taken care of.