How can Bitcoin become daily currency if the transaction can not be canceled? this will lead to massive fraud, because you can not return money for example for a damaged product...
look up multisig...
sorry, this is a fallacious argument. I'm going to take the high road and assume you don't know better. Frankly, and I speak from experience, PayPal is orders of magnitude more dangerous in this respect than Bitcoin.
With a 2 of three multisig, obviously you introduce a third party, but the issue can be arbitrated, adjudicated, and settle very quickly.
As for the issues with 'stability', I think this needs some looking at. It's not bitcoin that's unstable, it's people, and fiat money. Bitcoin's PRICE is unstable, because currently it's used primarily to move money of other sorts, or as an investment vehicle, therefore it's price is subject to massive fluctuation due to very small actual fluctuatons based on 'news', usually otherwise known as fud. Bitcoin itself, however, reliably adds a block approximately every ten minutes, and will continue to do so as long as at least two miners are connected.
It grew too fast this past winter. Anyone in the game long term has seen this before, several times. If, however, it starts being used for small, frequent transactions, as LN will make possible, then its market price is likely to rise slower, and fall slower, as it will be in CONSTANT use and demand. Scaling is the main issue to general adoption, followed by ease of use. Or at least that's my arrogant opinion.
Right now, or even in late December of 2017, Bitcoin is ridiculously undervalued compared to its potential utility. But we need some quick scaling solutions to get it there.
If Joe Public can use bitcoin easily from his Cell phone at Starbucks, he will. This will DRIVE the market, rather than following it. This will cause bitcoin to grow in price and stability. Price first, but the dips will not be as severe, because it WILL BE being used in small transactions with great frequency. This is the key.
As a store of value, it fails. As a speculative investment, it has been one of the best out there for several years, frequently outperforming the general markets by orders of magnitude. But it's a relatively small number of people using and adopting. New blood, recently, has mostly been on news, not on use. Given that the mainstream media gets it right about one out of ten (and I'm being generous, on any subject), this leads to a lot of ill informed people acting out of greed, FOMO, and misinformation. So it shoots up like a rocket.. and drops like one. But if the volume of transactions approached visa's hourly total in a week's time, the growth would be sharp, but not parabolic.
Yes, it can be a daily use currency. And likely will be. If it does not become so, another crypto will. The genie cannot be put back in the bottle, and fiat's days are numbered, sequentially.