Jeffbelize, most of the people here either visit San Pedro often, or wish they could. You are right, a lot of the people are so impressed with themselves, they are way to critical of others, and there those who feel it is their responsibility to educate and teach basic English and grammar and spelling. I have tried to get them to be nicer, and it helps for a little while, but then they bust out of their little cocoons and start it all over again.
Please don't let them keep you from going to Belize. Most of the people are wonderful. The "come heres" are the ones with the attitudes, not the "born heres".
I wish you a wonderful visit to San Pedro.