Hi. Do you physically train yourself and like it? Do you know his long term goal and his hobbies, is that something that is compatible with you. What did you talked about so far, familly plan etc...?
Strong personality and not shy is a good thing because if something is not right you will know very quicly without wasting too much time in the relationship. The bigger problem may be the age difference but that is something that may not be a problem, even in the future if it is not that much. I sense a little fear perhaps from what you tell that he perhaps will see other "younger" girls when he travel? If this is the case, as the French say "laisser la chance au coureur" (let the runner prove himself).