I haven't done the day pass at Sandals from a cruise, but I have stayed at a Sandals resort. The resorts are all-inclusive. They do not take money at bars restaurants, etc. so I assume they would be included in your day pass. Chairs at the resorts are first come first served, so they should be included as well. Towels are in a dispensing area and unless they have changed the policy since 2016 or these particular resorts are set up differently, you just take towels and drop them off. There is no scanning a card like Royal Caribbean does.
In short, I believe everything you ask about would be included in the pass.
