All of your other points are very good and I can't make any counterargument, but I do have a few questions:
We, in the west call chinese for "Han Chinese", is this very wrong, by that they are more of "Ming Chinese" or "Qing Chinese" (Chinese comes from Qing does it not? O.O )
I didn't know when Mandarin Chinese came into practice, but it makes sense it did under the Ming.
I at least FEEL like we in the west consider all modern chinese for "Han Chinese" and most speak "Mandarin". But what is the truth? When or what did they call eachother in their respective periods? Mings? Qins? What would be the correct term to use?
1. Provided that you are in fact referring to someone from the Han ethnic group, it would be correct to refer to them as Han Chinese. Like the term "Gallic" or "Persian" for something pertaining to France or Iran, Han is one of those historical idiosyncrasies which managed to retain linguistic currency long after the Han polity itself ceased to be.
2. The English word "China" derives from Qin, rather than Qing, most likely by way of Middle Persian. It was used in Europe long before the Qing Dynasty was a thing.
3. Mandarin is a product of the Jin and Mongol invasions: it gets its name because it originated from the royal court (which was dominated by foreign nobles and Han Chinese officials, or "mandarins") and permeated outwards. Before the invasions most Chinese would have spoke Middle Chinese, which was the lingua franca of the Tang and Song dynasties. After the Jin invaded in 1127, the Song were forced to retreat southwards where they continued to govern a rump state ("Southern Song") until they were annexed by Kublai Khan in 1279. It was during this 150-year period that Middle Chinese began to mix with Jin dialects in the north to create what would eventually become Mandarin, while the Song-governed south continued to speak Middle Chinese. After the Yuan Dynasty, this northern language began to be used all over China and soon replaced Middle Chinese as a lingua franca, but the furthermost provinces of the south and south-east clung to their Middle Chinese influences, which would eventually evolve into contemporary Cantonese (Yue) and Shanghainese (Wu.) This, at risk of gross simplification, is why Cantonese and Shanghainese are so named.
In a world in which the Jin and Mongol invasions never happened or were quickly rebuffed, China would probably speak something very similar to Cantonese today. In European terms, it is like the Italian to Mandarin's French.
Also I don't understand the Zhongguo point.
Frankly that's pretty obvious judging from the rest of your post. Grasping the concept is essential: you cannot have a serious discussion about what China is without it. It would be like trying to describe the virtues of a contemporary secular republic to a medieval peasant who had no concept of government beyond that of a divinely anointed monarch. You cannot grasp the concept of popular sovereignty if you believe that all sovereignty are bestowed upon certain individuals who are chosen by God, just as you cannot grasp the realities of "Chinese civilisation" without understanding the concept of Zhongguo.
If we use one definition of civilisation for China and another one for Rome then not only can we not answer the OP's question by definition, ("Rome can't become like China because Rome is Rome, not China, silly.") we ironically end up in exactly the sort of hyper-relativistic scenario you claim to criticise. If civilisation is simply what one claims it to be, then anyone or any state can quite literally claim to be any civilisation it wants. Right now, Italians call themselves Italians and so you consider them to be a separate civilisation from the Romans, from whom they descend. But if some latter-day Mussolini came along and declared that the state of Italy was to be renamed SPQR, its inhabitants were to refer to themselves as Romans, and then claimed that all of Italian history hitherto had actually been a continuation of that same glorious Roman master race, how would you refute this if enough Italians believed it for long enough?
You might think this a ridiculous strawman, but it isn't. You have no objective definition of what Chinese civilisation is beyond the fact that Chinese self-identify as "Han," therefore are indistinguishable in a civilisational sense from those who lived under the Han. Despite the fact they speak different languages, use different writing systems, pray to different gods, etc. and never minding the fact that the concept of Han = Chinese wasn't in continual use over the past 1800 years. It was certainly not used much under the Tang, for instance.) Because such a view rests entirely upon the arbitrary nature of self-distinction, it cannot refute a fascistic and fallacious retconning of history like the example above.
Replaced? Mandarin is an evolution from Middle Chinese and Old Chinese. It's natural that languages change. Latin likewise didn't stay the same for centuries.
It's an evolution but not a
direct evolution. Both Middle English and Low German evolved from Old Saxon, but one of those languages is far closer to the source than the other. This is because Middle English is awash with Franco-Norman influences whereas Low German is not. Thus, it would be completely fair to say that Middle English replaced Old English as the English lingua franca even though Middle English carries its own share of Saxonic influences.
Middle Chinese is a dead language, it doesn't exist anymore. Don't confuse other Sinitic languages with the actual Middle Chinese. Cantonese, Wu, Gan, Xiang represent other paths of language evolution just as Mandarin does.
I literally said "ancestor language" in the bit you quoted. By definition, Middle Chinese cannot be its own ancestor language!
To be fair, I suppose what I said could be misconstrued as "Middle Chinese, the ancestor language of Mandarin" rather than "the descendants of Middle Chinese." Suffice it to say I meant the latter: ancestor was a poor choice of term in this regard.