Questions about tying dollars to gold and/or silver

I’m trying to setup a local currency tied to individual stores of gold or silver and I have a few questions about how this would work. Here are my questions so far:

  1. How can the dollar have a set value when the spot price of precious
    metal changes daily?
  2. Does the amount of dollars in circulation increase when the spot
    value increases or is the dollar a direct representation of the amount
    of a commodity ($1.00=1 ounce of silver)
  3. If the amount of dollars in circulation increases when the spot
    value increases how do fractional increases in the value of silver add
    to the circulation? (how can you add 1/2 dollars or 0.66666 dollars to
    the system?)
  4. If the dollar is a representative of a commodity how do merchants
    price goods if the price changes? Would all merchants require a
    commodities merchant even if there was a paper dollar backed by
    commodities?
  5. If the dollar was tied to commodities how would anyone know what
    value the commodity was worth?
  6. If the prices of commodities are still artificially manipulated by
    COMEX and paper markets how can the value of the dollar reflect the
    true value of the commodity it represents?