Excellent work. Good idea on using rock wool instead of fiberglass. I hate working with fiberglass.
I like the way you took care of the vapor barrier to avoid puncturing it in the future. Vapor barriers are something we do not have in Las Vegas -- too dry to worry about moisture! I can leave a bag of potato chips open for a week and they are still crisp and tasty!
I wish it could be dry here sometimes, living near the sea comes with a price.
Add cold winters with lots of snow to that aswell.
The upside might be the green nature i guess you lack in Vegas.

I recently added 10" of blown fiberglass on top of the paper insulation as the gas company had a huge financial incentive to do so (they paid 1/2 the cost).
No. Infact that is a great idea and similar ideas have been shown on here on the GJ using a Winch.
4 nails each.
huray!