Here again China has a propaganda problem. China should always frame that it's the US that will start a nuclear war because they will as a last resort if they are losing. That way any context for China will be in the right to self-defense. The US always frames it that China will start the war because they want China in context that it's irresponsible hence why they think they a right to have nuclear weapons while China does not. Many Americans to this day and especially before the Wen Ho Lee scandal didn't know China had nukes. They believed if China had nukes, it would use them immediately hence why they believed China didn't have nukes because they would used them to try to destroy the US and the world already. Did China go crazy and try to build as many nukes as they could? No. The US taunts it has more allies so therefore more enemies of China. China therefore has the right to as many nukes as it takes to defend itself from all of them. China proposed a space weapons ban. The US rejected it. Because China is poor at propaganda the US was able to spin that as China lied when it proceeded at making ASAT weapons. No, the US rejected it and therefore that allows China to make them to counter the US so they don't have an advantage. But because China let the US get away with it and not threaten to start making them because the US rejected it, the US was able to portray China as unsavory and untrustworthy. China should put the US on the defensive and call for the total elimination of nuclear weapons in the world and if the the US rejects it then there are no restrictions to how many a country can have. The US doesn't want to get rid of their nukes because they need them as a trump card in case they're losing in a war. Take a look at how badly Americans are taking losing the war in Afghanistan. Take a look at how some are calling for killing Afghanis like a nuke would do but without nukes like that makes killing people in masses indiscriminately okay. They believe China would start the war is a given. It is more likely that the US will use nuclear weapons first. I was in a forum where some guy posted that the US isn't going to use nukes on a country first especially if the country does have them. I posted, "Hiroshima and Nagasaki...?" You have Americans that have already forgotten the US did they very things they believed the US wouldn't do and they used nukes immediately after the got them for the first time.
I don't think it is an issue. Even if China tries to state it is for self-defence they are just going to say China is lying, much like how despite the other aspects of military modernization being a justified action to get up to the same level as the West, it is framed as preparation for aggression.
A proposal for nuclear disarmament is a bad idea. It is very obvious such a plan will be rejected, outside of the situation in the Pacific there are justified reasons to continue maintaining them too. It will just be seen as a cheap move to be able to then say "we didn't want to, but the US rejected it so now we have to".
Despite this talk of going to full MAD levels of warheads, obviously, China is not going to deliberately start a nuclear war. This is all in the name of self-defence. I think it would be best to just keep repeating that, as no matter what China says, the West will always want China to have an air defence system made up of J-6/7/8s, HQ-2s, a brown water navy, and a small and unprepared (not loading warheads on missiles except in times of crisis and so on) nuclear force, and to them anything more than that is somehow illegal and evil. Trying to convince them otherwise is the same as trying to convince them to abandon their imperialist ways.