If you're driving back to PA on Sunday the 24th, I would recommend heading up to NE Tenn. to spend a couple days since you'll be going through that area anyway on I-81. Some recommendations: downtown Rogersville, downtown Jonesborough, Bays Mountain Park in Kingsport, Rocky Mount Living History Museum in Piney Flats, South Holston Dam (Bluff City) or Watauga Dam (Elizabethton), Rhododendron Festival in Roan Mountain, Davy Crockett Birthplace State Park near Limestone, getting off the interstate and soaking up the scenery in rural Greene, Washington and/or Sullivan counties (the area around Telford and Limestone is drop-dead gorgeous).
You'll find more things to do & places to go at the following links:
East Tennessee Tourism Guide – Plan Your Tennessee Travel Here (broken link)
NETTA: Visit Appalachian Mountains – Northeast Tennessee
I'm really curious about small town attitudes towards yankee outsiders.
One's attitude is much more important than where one's from. Generally speaking, East Tennesseans are conservative folks who are very proud of their roots; any disrespect or disdain shown toward them will probably be returned. Yankees (or any other "outsiders") who criticize and/or clearly look down their noses at the locals & their traditions aren't going to receive the generous dose of Southern hospitality we're known for. But the local folks are also about as friendly as you'll find anywhere in the U.S. Neighborliness is just a notch below Godliness in these parts; most people will bend over backwards to help ya out w/ anything within their means. As long as you don't take advantage of that and you're a man of your word, you'll fare just fine in E. Tennessee & you'll not regret your move one iota.