A few words on your characters that will help you flush them out better. He is a straight shooter that runs through any adversity with skill or hidden apprehension. His weakness is snakes. If they are perfect they are uninteresting. The next point on characters for know.
Characters are diverse.
If they are an educated person they talk in intellectual terms If they are a streetwise criminal they would use simpler words and some suggestive cursing. A woman talks different then a man and and has a different agenda to the same end. Give your characters the acid test. Can you mix up the voices of a character with another. You can lose your audience on this one.