Miserably bad? No one actually asks you to come and pay in gold coin, the system with gold backed paper notes eliminated the issue which you are referring to here. The system of gold standard got heavily abused in the end, but that was not a fault of gold as such or its drawbacks. Gold as currency has significant flaws (you didn't name them), but these are not relevant to its functions...
Yes but if you introduce a gold backed currency ,the same thing will happen again, they will just take it away.Or find ways to work around it.
The whole point of cryptographic currency is to eliminate the reliance on 3rd parties, would you trust a central bank of keeping honest books about gold reserves? Would you trust politicians? Would you trust the mint ?
I would not, since we got much better alternatives.
I wouldn't trust them either, but your claims (that gold is not a currency) are in fact unfounded and don't meet well with reality. There are gold coins minted in many countries, so gold is a currency, whether you like it or not...