Is it normal to think that china will become the number one superpower?

Absolutely, without a doubt. They won't need allies or friends. As long as the world continues to have their products manufactured there, they will have the world by the balls.
They have a huge population and most will do exactly as ordered by their government, their military is totally financially independent of their government and very wealthy (the scariest part of China's system) and many of the world's economies are tied to their production machines.
When it is their time, they will rule the world for centuries.

Maybe. China and the US seem to me to be the two main competitors. China and the US are both "nation states". To answer the question, you have to think about what a nation state is. I imagine nation states as having a dual role - as political structures and cultural structures. Now I don't know a lot about geopolitics, but it seems to me that in terms of economic growth China has a pretty good position relative to the the US, the current generally recognised superpower. However, the US seems to me to have a greater impact on international culture. You have American food and TV and movies shared across the world, and English - the dominant language in America - is still the main language of business. I doubt many people in the rest of the world could tell you as much about Chinese culture.

You can also consider military, but world war seems like an increasingly unlikely medium for deciding the balance of global power in the future.

American corporations have enormous name-recognition around the world. But I think when you start considering corporations, you have to consider whether they can really be culturally or politically tied to a nation. I think it's also possible that since the nation state is becoming less powerful, the position of "superpower" is becoming less important and could soon become obsolete. Corporations are increasingly exerting economic power over national governments. They currently have a great deal of control of the world economy, and capitalism is the main mode for spreading culture.

Conclusion: by the time China overtakes the US, which government is more powerful will be of little importance.

China will own the world. Thusly, it will make the rules for those who govern the world.

I think it will be China, Germany and Russia.

Ofcourse it will, it's been geared that way for decades now. Nostradamus actually predicted it to occur as it is now along with the second world war being started by a man named "Hister". The US is safe anyway as China owns most of it.

China is still at a big disadvantage because they are not as closely tied with their allies AND their allies are relatively weak compared to the west.

They are sort of like a giant trapped on a deserted island that needs to constantly rely on the west.