Qualifying is on Thursday, yes. Everyone with Double Down tickets will be able to see it.
It's been a year so I can't remember as much, but I'm pretty sure they don't thoroughly check bags.
In my opinion, it wouldn't really make sense to spoil a design in a casino parking lot. There's more than likely a design, they're just not going to waste it on people to spoil.
But yes, that's the design currently at Sam's Town.