Of course I wouldn't trust the government with the numbers--I wouldn't trust the government to tell the truth even if they had nothing to gain by lying. Misleading the sheeple is such a way of life with them, they probably enjoy it on its own merits.
Also, you have to understand that my idea is not intended to stand on its own (although it would be a start); but as a backstop to prevent an end run around some other tax reform proposal, such as the main topic of the thread.
My general philosophy is that money is the lifeblood of politicians, and if their supply of it is forever limited, then so is the chicanery they can get into with it. Force them to beg for every penny, and they won't have enough time or money to interfere in the lives of citizens with honest jobs.