To answer the question about being disadvantaged because of having "cheated" through Armageddon, I will use the same stock answer that all religions use:
God can read hearts.
According to the witless religion, if you "cheat", Jehovah knows it and you will get destroyed anyways. Supposedly, one can fool the hounders, but they cannot (according to the Bible or the Washtowels) fool Jehovah. According to them, if your heart is not in it, you die.
However, that stock answer does not answer the legitimate question about those who go above and beyond the requirements getting extra rewards. That was the original question on this thread, and I do not believe that there is any extra reward. You can do 200 or more hours a month of field circus and reach out for every "privilege" you can, and still not be any better off than someone that did just the minimum. Plus, the test after the thousand years is a stupid and specious answer--it is possible for someone that went gung ho and got in by huge amounts to become tired midway through, and die at the Final Test. It is also possible for the person that barely managed to get in at all to become more stable and reasonable later, and make it through.
Hence, even if you believe the religion, if you are doing more than the minimum, you are not only wasting time and energy but risking burning out. And, if you burn out, you die as dead as if you had done just the minimum.