It definitely depends. Sometimes the "feeling" business is pretty tough. You can get worked up really bad over something that bothers you. Transitions can be tougher for feelers as well, and sometimes they overlook the rational way to react to problems and wallow in self-pity too much.
A hero is someone who does the right thing without expectation of reward, just because it's the right thing to do.
I'll take a look at me for a second: What's the point for me to learn about typology? To learn about others and how I differ from them, and so with this knowledge I can strive to better myself in other areas. It's a tool to not only know, but to grow, and the more you grow the more self-fulfilling and probably happier you'll become. You think you're happy enough now, but there is no limit. So for a T growing more F, there is challenge met with reward. For a F growing more T, for a J growing more P, etc. Give me the next typology system you come up with, and I will look at myself in yet another perspective. I think people mistake dichotomies for talents where you're fixed to a certain pole, but they're more like natural ways of life that you have to explore and see for yourself.
Depends on one's definition of "fulfilled". Also, different people have different methods/ways of fulfilling their lives, and this is the same case with different types. So I would say to answer the question: No.