I think its really about the news of the looming Segwit2x that really push the price of bitcoin to $7000 levels. Those you have mentioned may have been somewhat contributed, but its not the main source of the current increase. Many are expecting that Segwit2x will really bring another free coins, but I don't know and I'm not sure about it so don't take my word.
We don't know if there will be a massive crash, but for sure there will be a correction. Now, if S2X doesnt go well, there might well be a crash, however, i feel that if properly managed, theres no reason, apart from the inevitable correction, for a crash of extreme proportions.
I don't think that there will be a major crash after Segwit2x, there might be some problems like miners not supporting it or mining a empty blocks but I think it can be sorted out after the implementation. What I worried most is that when some big entities try again to manipulate the price by making big sell orders right after the activation, we may see a ensuing panic specially for newcomers.