Sure, but China is not a suicide bomber. In the event that U.S-Chinese relations go sour, China is also screwed because its economic system is so entangled with the American consumer. 

https://www.quora.com/Is-Chinas-economy-dependent-on-the-US

I reiterate, China is not going to risk its economic security for North Korea. 

The petrodollar and its status as reverve curreny is what gives US advantage, so every country needs to have dollars if they want comodities like oil, but there are moves to replace it as China plans commonity trade directly in a gold backed note instead of using dollar. Currently China are the biggest oil importers and thus they need dollars for that.

It's not just the dollar that entangles China and the U.S. It is also the highly active American consumer base who purchase almost half a billion dollars worth of Chinese goods every year. The U.S is China's second largest trade partner after the European Union, and due to the nature of NATO a war with the U.S will likely bring many European countries in opposition to China as well. Again, they are not going to risk that for North Korea. 

http://www.zerohedge.com/news/2017-06-01/chinas-next-step-destroy-dollar

http://www.zerohedge.com/news/2017-09-02/de-dollarization-accelerates-china-readies-yuan-priced-crude-oil-benchmark-backed-go

China exports to US, yes, but there is no manufaturing in US anymore, everyhing is in China. If they block all chinese manufacturing imports, they have a huge problem: the lack of production capacity for these items that during the past decades moved to China, it will cause shortages in US suplies which will lead to inflation.

You can't build a whole manufacture structure overnight.

That is all irrelevant to the point I made. We are discussing the event of a war between China and the United States in North Korea. We are talking about what China would do if the U.S attacked North Korea. A war necessarily means that trade between the countries will stop. China loses all of the leverage you keep citing. The U.S has the productive capabilities to supplement a war-economy, which isn't focused on iphones and laptops, but on bombs and guns.  

My point still stands, China is not going to cut its second largest trade partner, for North Korea. The buffer zone and fallout from the dissolution of the North Korean regime are cheaper than losing trade with the United States and possibly expanding the war beyond North Korea (which would be a global catastrophe.) If the U.S attacked North Korea, China will likely secure/annex the border regions of North Korea and let the U.S take the rest. 

1. They aren't, at least not in this case.

2. Just like Russia they don't want an U.S. controlled country at their own border. Easy to understand.

the same justification that was used to destroy several nations in the middle east and kill millions of innocent people... and there are people here egging this on...

and then people wonder why there are "terrorist" attacks

what's funny about this whole situation is that supposedly its because north korean is arming itself with nukes....

the united states is the only country in the world to use a nuclear bomb on another country... and as i just said has been the country by a large margin most involved in perpetuating unprovoked attacks on other nations

The United States is not some benign creature, but it is obviously not just because North Korea is arming itself. They are also threatening the lives of millions of people. This is different from what the U.S did in Iraq by the way, where it lied about the reasons for the invasion. Below are some of the things North Korea has been saying. 

“The four islands of the archipelago should be sunken into the sea by the nuclear bomb of Juche. Japan is no longer needed to exist near us,” the committee said in a statement carried by the North’s official KCNA news agency."

“Let’s reduce the U.S. mainland into ashes and darkness. Let’s vent our spite with mobilization of all retaliation means which have been prepared till now,” the statement said.

The United States gave Imperial Japan (a fascist regime that attacked the U.S) notice before it dropped the bombs, and hoped they would surrender before then. To remove the context of the use of the nukes in World War II is not being rational here. 

I'm thinking that North Korea is having some internal problems, and the regime is worried. It seems as if the younger generation is having information smuggled in from abroad, and they no longer have trust in the elites in the country. All it takes is for some system of organization and revolution might be underway. Hence, the haste in their nuclear weapons and missile tests. They're desparate.