Lots of language and sexual situations, but no nudity.
As for the seating, yes, it is in a church with a center aisle. Most of the action happens at the front of the church, with a good bit also happening on scaffolding along the left side. I recommend sitting on the right side of the aisle so you don't have to crane your neck as much.
The three seating options are Peasantry (the back rows), Nobility (in front of them, but also the front two rows), and Royalty (in the middle, what would be considered "house seats" in a theatre I suppose). I had Nobility and sat in the front row and loved it. To be clear, the very front row is not used for audience seating, the actors are stand on it a couple times, so the second row is the first row of seating. If I go back, I would do Nobility again and sit in the front on the right side of the aisle.