Bitcoin will never go to zero. Why? There are too many billionaires that will buy the total available supply long before it can get to $0.
0n a long enought time line bitcoin, in its current form at least, will 100% be worthless. That day is when its cryptographic backbone is either broken or surpassed by computing capacity to break the public / private keys.
So yes, I completely agree with your agreement.
Wrong, there have been a few soft forks already. You seem to not know the history of bitcoin or what makes bitcoin bitcoin. You need to do some studying before discussing this topic.
This is not a hypothetical, I will buy the remaining supply given a steep enough discount. At $1 BTC, the total supply would only cost $21M (not a lot of money). I can think of at least 5 peers that would do the same.