It's much easier to see a skyrocketing in price than a fall of 70% in price. I don't think bitcoin will fall to 100$, it's a very dramatically down and it would represent the end of the currency, who is waiting for this will wait forever.
The old times of bitcoin aren't the same we have now. Bitcoin economy evolved, it's not so unstable like before.
It could if something happened, as of now there are debate between to keep the original block size and to increase it. Alot of people will start stocking up and when the chain split, nobody knows what will happen. The worst will be that most people will switch to altcoin and leave bitcoin aside so price might be lower
yeah it is possible, there are many problems that exist in bitcoin including fork and you say. when the user started to get tired and lose confidence in the bitcoin, and large-scale migration. of course the price of it will happen