So way too busy this weekend, but I can't wait to have some time to give this a go! (First time through, I couldn't find one of the maps, so I skipped this. Boo on me.)
As far as retailers letting under-agers buy/rent what they really aren't supposed to, what I've noticed is that in many cases, the people working the registers probably aren't old enough to be able to legally buy/rent these items either.