Making gun smuggling transfer in a Vegas hotel would be industrial strength stupid. Literally a thousand better places to do it without the crush of people and security.
I am not saying he wasn’t a gun trafficker, just that doing in a high rise hotel is/would be dumb.
That’s pretty much a given I think it’s more likely that Paddock was a patsy and a useful idiot to some of the powers-that-be I don’t see him designing this thing as an OP