after been at 900 usd, now is down to 500, is it the end of BTC? I think it could.
What do you think??
No, even
BTC 1 = USD 10 is perfectly fine for Bitcoin to work as a currency.
Not true. Everyone would stop mining. Electricity costs and costs of hardware would become prohibitive.
There must be a minimum price per bitcoin for the miners to make a profit, otherwise they wouldn't do it.
For the network to function it would be enough if a single person mines on his smartphone.
If miners don't make a profit they stop (in reality not all do it), but unless they all stop at once, difficult goes down and the Network still functions.