On many occasions I've ridden my bike on the road all the way from the ferry to Costa Maya - staying on the road unless it was a stretch where "road" ran down on beach. I encountered one stretch of dead-end road where a resident has chained off a public road, calling it private, but there is an excellent alternative route, well traveled and well marked. Whether navigating that "blocked" road or all the others, I have not encountered any wires, spikes etc.
Why would residents be annoyed ? Noisey drunken drivers who drive fast and reclessly hitting dogs and people on bikes, folks tossing beer and water bottles in the bushes, driving through people's yards and gardens, walking right up to people's private homes and peering in the windows out of curiosity. This island is a tourist destination, but also a real place with real people who get up early and go to work, who have lives and who want a relatively normal existence. Guests need to remember that, and show the same level of respect for our homes and our daily lives as they would demand "back home".