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How could you Not carry your DSLR on vacation?
Really, though... if you keep it simple, I'd bet you'd be able to have fun without a lot of paranoia, and when you get back home, you'll be so glad you have such great images from your trip...
Nowadays, larger DSLR-type cameras are common enough that you may not attract as much attention as only a few years ago...that said, I think the tripod would tend to focus attention on you as a "photographer", more than just a casual tourist, so I personally limit my tripod use to the times when I'm concentrating on little else but photography...
Playa and Cancun are tourist-oriented areas, and your idea of taking a simple kit out and leaving other things in your room sounds like the way to go...