It sounds like you are under the impression that the entire ship is going to be walking past your patio. That is not true at all. The havana area is much quieter, and you have to have a wristband to be in the outside area. There are really very few people around that walkway.
That is not what he said at all. The large exchange of money was the problem. You cannot play any games that involve money outside of the casino. You are free to play games wherever you want.
It is OBC, not a discount on the cruise. It does not matter who you book with. Download the Stockperks app, it is very easy to claim the OBC. All they need is proof of ownership.