Ricky -
I too have a ways to go to understand and integrate many answers, and that is keeping me very busy, especially since joining the boards and podcasts and everything at FDR, and that, as I told them at the mystic site I used to frequent, has indeed become my priority.
The connection you mention between happiness and rationality and mysticism is another really good starting point, too. The right reasoning and the right mysticism should both bring happiness, I believe.
Rationality can be rather suspect, or what conclusions rationality has wrongly arrived at, let's say. René DesCartes - Mr. "I think therefore I am" - reasoned that animals did not feel pain like us, by what process of thought I don't know. For example. I imagine the cold, rational scientists over how many decades carefully measuring the results of their experiments while a background of animal screams and shrieks continues on and on. Rationality as well as mysticism can be pictured in an unfavourable light.