Cryptocurrenccy is a term that covers more than Bitcoin. Bitcoin makes up roughly 30% of the cryptocurrency market capitalization.
One thing about bubbles that is being underscored. Bubbles tend to occur when something is overvalued in relation to its fundamental metrics. Bitcoin doubling its userbase every 12 months or so, and coinbase reportedly having 100,000 new sign ups per day could imply that bitcoin hasn't hit its all time high, yet. Bubbles tend to occur when growth statistics flatline and value continues to increase without support. With bitcoin growth and price increases appear to keep pace with each other, which could imply there is no bubble as price hikes are merely a product of natural growth, etc.
Sound reasoning. Bitcoin price has inflated many times over the years. It has had major corrections as well. A correction is very possible.
A crash is certainly within the realm of possibility. Emotional investors are a huge contributing factor when it comes to crashes and there are plenty of them that have invested in Bitcoin. Even if it does who cares. Crash does not mean Bitcoin will disappear. As long as the community has interest it survives no matter what the price.
Amazons stock crashed by more than a factor of 10.