RCI excursions always get priority; suites and Pinnacles generally get escorted to a separate tender area by the concierge. Only one passenger needs to get tender tickets for the entire group.
RCI does not inspect any medications unless you carry 1,000 of anything. doctors' notes, prescriptions, or original bottles are not required for the TSA or RCI.
You could never buy as much as you wanted.
There are certain islands (mostly USVI) where if you buy one locally produced you can get more. Please check the CBP website.
Having said that, they rarely check anymore. It's self-reporting.
There is a service fee for withdrawing cash in the casino if it goes against your credit card. 5% The casino is charged an interchange fee by the bank, and they pass it along to you.
Refundable OBC is entirely different. It's against Visa and Mastercard rules to charge you for a credit back to your account.
OMG, we have been charged $900 at the Next Cruise desk when booking a suite. That was the policy 5 years ago because people were abusing deposits.
Probably the same myth as booking with a TA gets you a group rate. This is not a debate, the rules have changed.