I think the most important things to be concern
I think the most important things to be concerned about regarding retiring abroad is your honesty in answering the question: Can I handle change. When you decide to retire abroad there will be many changes in your life.
You may not see your family and old friends as much; you will need to get used to a different pace of life; it will take time to figure things out, meet new friends, locate stuff you need, get things done (and this can have a tendency to drive you nuts).
A new friend who just moved to Panama in my community is frustrated because it is much harder to get things done in Panama than back home in Canada. The language is different, the "manana lifestyle" is all present and basically things just move much slower here than in North America ..... but for me this is great. I needed to learn how to slow down, smell the roses and relax. Now after living in Panama for roughly seven years I have made great progress.