I think you have already got the answers to most of your queries. However, I will address one since I think it hasn't been addressed properly.
Q. Its backed by Gold but how do I cash this out for Gold? Can I send my tokens in for grams or ounces of Gold?
A. You cannot and that's very much reasonable. You see that every GOLD Storage token is backed by equivalent amount of gold in the valet. Currently there is 9,196g of Gold which could be verified on site. So there should be equal amount of GOLD tokens, right? And yes, there are exact 9195.327 tokens currently in circulation which could be verified from here: https://etherscan.io/token/0x0d16450d347c12c086d6c94c76c5aaac35ea07e0 , Now if you convert the token for Gold, it will reduce the supply of gold from valet but the supply of tokens will remain same. This will reduce the value of tokens since there will be more tokens in circulation than the supply of gold in valet. Sooner or later, if everyone starts converting token to gold, gold will dry from the valet. Hence, it is not viable to convert the gold token to physical gold.
Also, you should know that it isn't the shiny physical metal that creates the value of Gold. But the idea that such metal is scarce and precious actually creates the sense of value in the mind of the people. This is the reason why Gold is so much valuable. Gold Token on the other hand is equivalent to the value of gold since equal amount of gold is kept in the valet. Thus, you shouldn't see the Gold Token as token but the gold itself. It is as valuable as physical gold. Holding Gold Token is 100% same as holding physical gold. It has exact same price and high liquidity.