China's "No First Use" nuclear weapons policy is outdated and need to be revised, no serious military has this.
It's a useless policy that opponents frequently mistaken for weakness. The whole point of having nuclear weapons is deterrence and if you are pledging not to use nukes, enemies will know that they can force you to fight a conventional war and not worry about nuclear strikes. China is still committing to conventional military first and will only use nukes in retaliation by getting nuked first.
The West fears the Russian military (which has a fraction of the budget PLA has) to this day simply because Russia has stated clearly that they will use nukes first, they will use nukes against large scale conventional attacks and they will nuke countries with no nuclear weapons if threatened. This means that whenever fighting a war against Russia, Russian nukes are always on the table. Basically guarantees that Russia can't lose a conventional war.
More importantly, China's No First Use policy is hampering a solution to the Taiwan problem. If China got rid of this silly policy, will the U.S. and allies dare to threaten China with military intervention?
You don't know what you are talking about. A no first use policy is the only option if you consider nuclear weapons to be weapons of deterrence rather then weapons of war, which is the only reasonable view. China has the most balanced and intelligent nuclear weapons policy by far of the major powers, and a clear indication of this is how far US arms control negotiators are going to cast doubt on the credibility of China's no first use policy. I don't even know how you can possibly think nuclear weapons use would be at all justified in a conventional conflict, and no, Russia has not said they will use nukes first, the "escalate to de-escalate" myth is an invention of US arms control negotiators as well.
If you still don't understand, think about it this way. Nuclear war is the worst possible scenario for both sides of a conflict, and in any scenario where a nuclear weapon is used, there is sure to be a nuclear response. Therefore, any nuclear weapons use by any side directly results in either the destruction or unacceptable losses to both sides. The only exception to this is a "perfect first strike", where one country's initial strike completely destroys the nuclear forces of another, and this is fantasy- it is not possible. This, however, is what both the US and Russia have been pursuing, and is the sole reason for their absurdly large nuclear arsenals because of the arms race in pursuing this. China, with its far smaller arsenal, does not pursue the fantasy of a "perfect first strike", and instead maintains a small enough and a survivable enough nuclear force that makes it impossible for a country to deliver a "perfect first strike" to China. With it's no first use policy, China averts a possibility of a costly arms race, and simultaenously vastly reduces the risk of an accidental nuclear war.
As a concrete example of China's no first use policy at work, look at the situation on the Indian border. Both countries are nuclear armed states, yet nuclear weapons risk has not been brought up at all. This is a good thing, and vastly reduces the possible risk of a escalation spiral.
For your dumb hypothetical Taiwan scenario, lets map this out. Say China gets rid of its no first use policy, and swears that it will nuke anybody that interferes with its invasion. Because this would be an exceptionally dumb move, the US does not believe it to be a credible threat, and intervenes anyways. Then what? China nukes the US? China nukes Guam, and gets Hainan nuked? Think about things before you suggest them.
China's no first use is a good policy, and something every Chinese person should be proud of. Arms races are possibly the single dumbest thing on the planet, and the fact that China is able to avert one by a simple no first use policy is something everybody should be grateful for.