Belize might be on the dangerous side for honeymoon adventuring. I have heard good things about Honduras and Costa Rica, though. Staying on small islands may keep the crowds down, but also limits nightlife.
I was just looking into over-the-water-bungalows, and ran across this website:
This place rents motorcycles on the Island of Roatan, off the north coast of Honduras. Cruise ships stop there, so the port areas could be crowded. Staying elsewhere on the island may be the right balance:
Congrats on your upcoming wedding, and have a great time!