My biggest problems with Bitcoins is if fluctuation of the price comes.
and then sometimes my transaction is extremely delayed before my confirmation
comes in into my email

Right but at the same time we also have to understand that there are fellow bitcoiners who earn a lot of profit with just this. I love how the price fluctuates and gives us opportunity to earn with it.
Exactly someone takes price fluctuations as a threat and some view it as an opportunity to make quick profits, and people will really hate if price remains stable for a long time.
Yes undoubtedly bitcoin have a problem of price fluctuation. But sometimes its more excited when the price of bitcoin increases. But i dont think bitcoin has more bigger issue than this.