Hi Michael,
1. You will enjoy this experience from 7.30 pm to 11.30 pm and yes, you will have the privacy during this period
2. Its open rooftop and yard, but in the event of heavy rain at the start, The Unexpected may postpone the booking.
If rain comes mid-way through, they have shelters and can continue with your session unless it is not safe to do so. If they have to cut short a session, you can book a new future session at no extra cost.