I just try to find the major reasons for the very high volatility of bitcoins price we all encountered over the last years.
1) Exponential Growth ( in trust and usage)
It's clear this is a very strong reason to cause price volatility, since we have double and double of requesters that all needs to get coins from a scarce bitcoin supply.
So we see price squeezes all over the time (more up than down). Further we have no or lost experience with such exponential growth process esp in money (last adoption was gold some 1000 years before)
2) Evaluation Base CCY ?
I have the strong suspicion that bitcoins volatility is positive correlated to the volatility of the lowest trusted fiat currencies' volatility in the world.
Sadly I cannot proof this by averaging the historical volatilities of a 'poor's currency basket' of (Zimbabwe$, Venezuela$, Egypt pound, Jemen slotty, Syria Dinar,..xyz...) but I estimate, that we have same volatility there as in bitcoin. And all people living in those countries should be way better off with bitcoin and it's vola!
We just see and measure BTC/USD - volatility is high, but we forget where it's based on - on the poor ccys all together - but they are dominant here.
3) Heterogeneous / Fragmented Markets
We now have some 100 different exchanges and local places where you can exchange you bitcoin against any other fiat or crypto. There is no condensed order book / matching for a trade and limited arbitrage due to capital protection of some states.
I'd guess we'd see a fraction of the actual volatility, if we would have a (ideal) single world exchange, where all must trade BTC/USD (USD is just a default example for a world fiat and rest crypto ccy) .
Any other reasons you could see?
I cannot agree with your reasons stated for I think none of them is the reason of Bitcoin being volatile in nature.
Number 1 is not a reason why Bitcoin is volatile, it is a result. Bitcoin is very volatile that is why we can see an exponential growth in Bitcoin's price.
I do not know why relating and comparing Bitcoin to an existing (or not) currency out there would justify and answer why Bitcoin is volatile.
Number 3 does not reflect volatility, we can see varying prices from different exchanges because of their own policy. These exchanges are businesses wherein the owner/s dictate/s how much is the price of Bitcoin in buying and selling with respect to the actual value of Bitcoin. So there is no volatility in here.
The main reasons why Bitcoin is volatile are:
1. Decentralized - Being decentralized, no entity dictates or controls the price of Bitcoin which then leaves to the market to decide for Bitcoin's price. This leads to number 2.
2. Demand and Supply - Since the market dictates the price of Bitcoin, the only variable that is measured in here is the volume of demand with respect to the available supply in the market. The demand and supply of Bitcoin in the market changes every time. This is the main reason why Bitcoin is very volatile in nature.