I understand this debate has been quite the topic in China as well recently and created a lot of controversy but I'll address your points.
1. I do realise nukes are stronger so what though? 300 isn't enough when some might fail, many will get intercepted, and a huge portion will get destroyed in first strike. We're talking a retaliation to first strike assuming early warning fails to get all missiles into the air.
2. No I don't think they'll tolerate hundreds of cities lost (they don't have hundreds of cities <1M population anyway) but that's not what's being talked about. I believe it takes thousands of warheads of achieve this. With 300, China would be lucky to take a few cities.
3. Because MAD calls for all associated stakeholders to be dragged in. It's principle. If all missiles are on the US, what if US government commands are actually originating elsewhere? What if the US is just the henchman? Europe is not a lesser antagonist and involving them also ensures they are responsible for preventing their "allies" from launching first strikes. MAD works with some nuance. Not only is "outside" parties involved, but they are all stakeholders because when one dies, all die with them and that principle prevents first use or at least gives consequence to third parties in an effort to get them involved in actively pursuing de-escalation.
4. Survivable second strike is good enough?? lol come on. It's never even been tried and thank God. How could one who "knows what they're talking about" seriously even entertain a flimsy theory like that as if it's 100% solid.
5. Dude please. I understand the nuances of no first use. Instead of continuing to write "the no first use policy is based on rock solid strategic reasoning that you would understand if you read anything about it" why don't you actually explain it so that we can pick it apart slowly. Why is no first use solid strategy in the context of providing superior deterrence?
6. I explained why having a small stockpile is stupid. You just said having more than 300 warheads is beyond retarded. Explain it like I explained my perspective.
I'll respond in good faith, since you seem to be doing the same.
1. Some missiles might fail, sure. Not many will get intercepted though, American homeland missile defense does not actually have the capabilities to do that considering that the GMD, the main system that will be doing the interception, has never been tested against MIRV'ed missiles. If Chinese missiles are deployed smartly, it's very unlikely that many of their mobile missiles get destroyed in a first strike, there's a good (though somewhat dated) paper by Glaser and Fetter that describes how difficult it would be to track hundreds of TELs moving through underground tunnels, though the liquid-fuelled DF-5s are likely impossible to defend. China's mobile ICBMs are very survivable, and if the silo'd ones move to launch-on-warning as is rumored to happen soon, that complicates the calculus even more.
2. Hundreds of cities aside, I highly doubt that US leadership would tolerate even ten cities lost in a retaliatory strike. A few cites make up that vast bulk of the US's economic potential, and if the US gets hit back, even if the country survives, it's unlikely to be relevant ever again.
3. My resistance to nuking Western Europe mainly stems from the assumption that China doesn't have extremely large reserves of spare ICBMs, but I don't think that assuming that the US would be the "henchman" in any situation involving Europe is realistic, especially when it comes to nukes. Because China has some shorter range missiles that can be equipped with nuclear missiles, I fully expect the US's Asian allies to be nuked, however, if it comes down to it.
4. Survivable second strike has never been tried? I'm sorry, but I don't see how that's a valid criticism, considering that a disarming first strike has also never been tried, and is by any metric far more difficult to pull off.
5. I've explained it before in this thread a while back, but the calculus of a no-first-use policy is that discarding the ability to strike first both hugely lessens the requirements for the nuclear arsenal, but also contributes to strategic stability and the possibility of an arms race. Chinese nuclear doctrine was created when the US and the Soviet Union were deep into an arms race, which had hugely damaging impacts on either country's human development and economy, and China, more specifically Mao, decided that it never wanted to be party to an arms race. A no-first-use policy does not provide equal deterrence in non-nuclear issues, for obvious reasons. However, assuming that the country in question has credible second strike capabilities, the deterrence provided in terms of a first nuclear attack would be identical to a strategy like the the Americans have. Put quite simply, the no-first-use strategy detracts nothing from deterrence from nuclear blackmail, compared to a "traditional" nuclear strategy, while providing large benefits.
7. Having a massive stockpile is not only relatively pointless, considering that only a fraction of that number is required to have deterrence, but also hugely costly to maintain and upgrade. Probably most importantly, it also invites arms racing, which is what happened between the US and the Soviet Union. If you don't believe that a few hundred warheads is enough to provide a reliable deterrence, due to issues like missile defense, it can justifiably be expanded, but you seem to have a far higher opinion of the US's missile defense then anyone I've met.
