I agree that Groban does not make or break Great Comet and you should see it regardless, BUT just to correct the above posters so that you don't get your hopes up, the composer (Dave Malloy) is NOT scheduled for this performance. According to the announcement, he is doing 10 performances all of which are in May and June, none in April.
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)
Ugh, I hope not. I've been listening to the original recording since I bought an advanced copy at Kazino three years ago. It's one of my absolute favorites, it would be amazing to get to be a tiny part of the new recording.