There is no burden to serve the living God. The Bible declares that we are to obey the Commandments of God. That is the work we do. Works are the other side of the same coin of grace and faith. That is why James taught faith and works, not faith alone nor works alone. We know that we can not earn our way to heaven and we do accept the grace of Christ, knowing that without Him none can be saved. Perfection comes as we place ourselves into the grace Christ offers as we do his will.
We do strive to keep the commandments, but we are also taught that we are not expected to do more than we can. We do as best we can and rely upon Christ's grace for what we cannot do.
As for original sin, we accept that it was taken away through the sacrifice of Jesus Christ. Therefore we are not punished for Adam's transgression, but only for our own sins that we have committed.
We believe that we receive no witness until after the trial of our faith. We believe faith is believing in what is not seen but which is true. The archeology of the Americas is still 90% untouched. Whereas the archeology of the old world is extensive. I have yet to hear of the uncovering of battlesites of Aztecs against the Spanish. Lack of evidence is not evidence of absence, it is just a lack of evidence because one has not found the right location. Evidence of the Book of Mormon's authenticity is found within the Book of Mormon itself. I know that Joseph Smith is not the author of the Book of Mormon.