But Li Zicheng didn't have to be. It isn't like the Shun Dynasty was bound to fail even though it was founded by a ruler of lowly birth. And it isn't like authoritarianism will produce a failed state from the get-go. Imperial Russia was horrific in terms of its secret police and levels of secret police bureaucracy, but it created one of the largest empires in the world and at times produced good results. Besides, the imperial system would end up correcting itself in the end or get overthrown in favour of a republic. And something tells me a Han dynasty might be more perceptive to those issues than Qing was, especially if a school of thought re-emphasises Li Zicheng's social position toward peasants.
Even if Shun couldn't conquer as much land as Qing did, I think it could still defeat Southern Ming or any other loyalists and go on to conquer at least one of the areas Qing did. I'd guess Manchuria would be the obvious target since it's closer than Dzungaria.
The Shun was doomed from the beginning.Thing is that Li Zicheng wasn't a revolutionary.He was merely a man who wanted to take the luxuries of being emperor by force but none of the responsibilities.Both Li Zicheng and his army wasn't there to help or save the people,they were none other than marauders who try to make a living but plundering the hell out of the common people and the wealthy alike.As I've described in one thread,they were basically ISIS but without the religious drive.This is the reason why the popular support for Li Zicheng and his supporters eventually ran out and unlike his time against the Ming Dynasty where he was able to repeatedly get come backs after defeats and defeats,the people abandoned him.
As for authoritarianism,the thing is that China hasn't had the level of authoritarianism it had since the Qin dynasty.Prior to the Ming Dynasty(I don't know much about the Yuan,so I'll skip it),officials had the right to criticize and even reprimand the emperor.You get you and your family executed if you try that in the Ming and Qing Dynasty.Tsarist Russia repressive regime ended up having Russia become a backwards country that could never fulfill it's full potential,furthermore it mostly controlled wastelands.The amount of authoritarianism in China caused by Ming and Qing caused backwardness,corruption and inefficiencies.The fact that the emperor had to create
four secret police organizations serving at the same time and also spying upon each other times you just how much bureaucratic red tape and how insane it is.Haijin,which is an form of authoritarianism practiced by both the Ming and Qing dynasty was also a major reason why China became backwards.
But it's not just a government thing, the idea of the natural borders of China was quite prevalent in the late Ming in elite society in general. The Qing changed that totally - if there's another Han dynasty we don't know if this will happen, or if they will simply follow late Ming precedent with a primarily off-hands approach in Mongolia and an ignoring approach to the ocean.
My point is that most of the world did perceive the Qing as China. By contrast, not too many Afghans perceived the EIC as an Indian empire.
I agree the Qing inherited a lot of the shitty Ming system, but the Qing eventually reformed a lot of the system, e.g. the Yongzheng Emperor reforms officials' pay schemes to lessen corruption.
I don't know if the Manchus really killed more than the rebels. Besides Zhang Xianzhong, think of events like the destruction of Kaifeng.
Problem is that the corruption's back immediately after Yongzheng's gone.As for there being a natural border of China,emperors generally don't give a damn about that,especially the military minded emperors who establish their dynasties.A major problem that came up with the Ming dynasty was that Zhu Yuanzhang set up a whole list of restrictions for his descendants that conservative officials were able to use against the emperor if he tried to do something different.Many of the emperors simply didn't have Zhu Di's amount of authority which could be used to break the status qu

ne thing that should be realized is that most Confucian writings suited the tastes of a dynasty's founder.