Well, I'm not going to ask to the first question because it is too complex.
But...You're forgetting that the current system has a high cost, it is
more expensive than the gold standard. Mining gold is cheaper than
managing central banks, banks, "fixing" bank runs, etc.
You're assuming paper-money is free for society, which is not the case.
When you say "miners don't do anything useful", you're comparing the
cost of bitcoin-money to the cost of the current system which you
think is free. Miners are making money possible, and that's a very
valuable service for society.
1)
Both collaboration and competition are good. The problem is not
competition, the problem are economic rents. The problem is that big
companies buy governments.
Interest leads to concentration of power, that's another problem, but
freicoin supposedly prevents that. I recommend you Silvio Gesell's
book if you want to understand the motivations behind freicoin.
2) Gold is cash-money and cash is NOT a store of value. That's a very
common error. Any form of cash could lose most of its value overnight.
Most of the current value of gold comes from the fact that it is money
and competes with other currencies like usd and eur. But even if gold
cannot be printed it could be demonetized, just like silver has been
many times.
I'll cite Gesell to explain my brave claim about the store of value:
"The anomaly of the physical junction of the medium of exchange and
the medium of saving is still more obvious if we suppose that, as in
Joseph's time, a series of fruitful years is followed by a series of
bad ones. During the fruitful years the people would of course be able
to save, that is, to pile up a mountain of paper-money. If during the
following years of scarcity the people wish to utilise this mass of
paper it becomes apparent that there is no supply to balance the
piled-up demand."
If gold stops being money (losses the component of its value that
comes from being money), it would become more save as a store of
value. But there's nothing inherently wrong with hoarding commodities,
that's like an insurance or a bet that they will be more needed in the
future.
The only problem is hoarding the medium of exchange.
3) The interest is nothing but the price of savings. Without
demurrage, it must be always positive or the lender will prefer to
just hoard. With demurrage it is better to loan at zero interest than
to hoard.
Not sure if I have answered properly to all questions.
--
Jorge Timón