We just came back from a week at Amish Acres in Nappanee, IN, and we live fairly close to Kalona, IA, two of the places you mentioned in your first post, so we have fairly frequent contact with the Amish.
The reason there is so much variability in their habits is that each community is free to decide which of the modern conveniences they are allowed to use. So each community can be very different from another one that may be nearby.
In general, the Amish prefer non-machinery ways of doing things. They are friendly, polite, and open to questions from us, who they call "the English". They are known for their ability at forgiveness - remember the Amish school shooting in Lancaster County, PA, and the Amish inviting the gunman's wife to the funerals? Their craftsmanship is legendary, as is their baking.
The one thing to remember is that it is against their religion to have their picture taken, so don't ask them.
And by the way, do you know what an Amish Haystack Dinner is?