Jamaicans are very proud people. They live in a very poor country. If you were to talk to someone and the person you talked to ignored you, you would get a little upset (okay maybe a lot upset). That happens quite a bit to the people of Jamaica as people sometimes are afraid of them. Show them some respect and it will go a long way. If someone wants you to go into their area to look around at their carvings, clothes or whatever, a simple "no thank you, mon" will go along way. It shows respect. Show them a little respect and they will not hassle. Once you get to know a person and they know that you understand them, they will great you with "respect".
As for Irie, it could be used as a greeting of hello or even goodbye. It is also used when everything is going great. If someone asks how you are doing, respond with "everything's Irie". Again, RESPECT!
Joe Canino CTC, MCC