I think the advice you've already gotten is good. Just come to Belize and spend some time poking around, and you'll quickly decide whether it's for you or not.
One other piece of advice I have is to travel around the country before settling in at any one place. San Pedro, for example, is great for what it is, a resort island, but it's only one tiny part of Belize. Corozal or PG for example are as different from San Pedro as night and day.
Persoanlly I'm a big fan of Corozal Town and environs as a place to live -- living costs are a third of what they are in San Pedro, or less. The weather is good -- less rain than in Atlanta -- crime isn't a major problem, and you're next door to Mexico for good medical care and inexpensive restaurants and shopping.
By the way, I just learned that my new book on living/retiring in Belize, Adapter Kit: Belize, is now shipping from Amazon.com and other major bookstores (even though I haven't even seen a copy yet!)