For me, bitcoin needs regulations and rules. It will help us especially to those participants how important bitcoin to them. When someone will follow it, it will show that they are like to learn more and want to get knowledge about bitcoin.

there are a lot of reasons that people are not accepting bitcoin as payment and being decentralized is not one of them.
here are some of those reasons:
1. lack of customers willing to spend bitcoin. there may be a lot of bitcoin investors but only a small percentage of them are spending it.
2. high fees. which may be temporary now but that throws people off.
3. high volatility. unless you are converting back to fiat immediately or believe in the future of bitcoin, it is tough to accept a volatile currency.

Bitcoin is not needed by anyone in the form of a payment system, because it does not possess the required characteristics of the payment system. There are other companies that can match. Here the question is not in what that specific crypto currency, but in the market as a whole. For example, in Japan legalized the crypto currency, now you can accept payments and organize payment systems on the basis of different crypto-currencies, and not just one. For the adoption of such laws, of course, approval of the regulator in each country is necessary. I think those countries that block and reject crypto-currencies will lag behind their IT development from those who will legitimize them.

of course, bitcoin needs to be regulated, otherwise there will be chaos

I don't understand what OP is trying to say,what do you mean by bitcoins need regulations?or it supposed to be bitcoin usages needs to be regulated?
Decentralization is the main reason that bitcoin was invented so we can't do anything with that.
No,it is already in the better form, bitcoin doesn't need to be regulated.Only the countries have to adapt to the new technology.

if you mean the government regulation, well, bitcoin must stay away from such regulations for the greater good of humanity and mankind.

With the news of exchanges being hacked (Mt.gox, Coincheck which occurred today etc.) all over the place, everyone is stepping further bitcoin. Regulations are always welcome as It could attract people and make them feel safe.

We could never forced any country to accept Bitcoin and we have no power to compel any country and its citizen to change their stand on the matter. The sovereign power of any country will always be in the government not unless there will be a big revolution that will take that power away from them, we have no choice but to be at the mercy of those people in the government. Those people who can't accept this reality will continue to dream on and I admire them for that.

Those countries who accepted and recognized Bitcoin established their own regulatory framework that will cover the selling and buying of cryptocurrencies including the issue of taxation which can be important for any government. We have no choice but to accept the fact that regulations can mean a lot if it is in exchange for recognition of cryptocurrency. Rather than ban I always prefer regulations.

No. Crypto currency itself is able to regulate itself on the basis of existing institutions.