You admit that its achievements were real and that it was happening, that's a start. The Carolingian Empire WAS most of Western Europe, at least according to your own definition of the former parts of the Western Roman Empire. There was also Islamic Iberia which you claim for it to have had some achievements, so there's that. The Carolingian Renaissance was important, marking a period where there was some revival of Greco-Roman culture and it did have many achievements, see Carolingian Minuscule, new styles of architecture and art, centralisation of government, building of churches and schools etc. No known individuals? Paulinius of Acqueilla, Peter of Pisa, Theodulf of Orleans and more. As for nothing special coming out of Western Europe: This is evidently wrong, this paragraph partially shows why.
Islamic Iberia? Please. They weren't even politically part of Europe, they were part of the Islamic world at that time.
Let me repeat what people have already told you in this thread: ''Dark Ages'' as a period of constant stagnation and decline are a myth! Me and others have already mentioned the renaissances for one. On the Mongols and Asia I can't comment as it isn't my forte but it looks like other people are pointing out your mistakes there.
When they win general European war after general European war in short spaces of time it has to count for something. The Vietnam part is effectively a non-comparison. What important influences? Besides the military advances they were somewhat ahead of their time after 1721 during the ''Age of Freedom'' I would say. People like Carl Bellman, Olof Rudbeck the Elder, Olof Rudbeck the Younger, Emmanuel Svedenborg, Karl Linneaus, Axel Oxestierna, Arvid Horn are some of their most well known cultural, scientific and political figures, they are just the ones I can remember off the top of my head. Your notion of development is presentism and disregards the actual historical reality. In the, let's say, 18th century Sweden was rather average and if not more advanced than some countries in regards to politics for example.
While technically true, the Napoleonic part is again simplified and ignores much of the events and context of the age. For the stagnation: See above.
Austria was a major power that rivaled France and fought many wars with them. Let's consider their time as a great power to begin in 1440, when the first Habsburg Emperor of the Holy Roman Empire took control. Austria-Hungary lasted for 52 years (1867-1918.) while Austria's time as a great power lasted almost 500. Far from short lived. Let's consider Sweden's time as a great power to begin with the ascension of Gustavus Adolphus in 1611 and end in 1721, 110 years of great power status.
While smaller than the Carolingian renaissance it shows that the notion of them stagnating and not doing anything is untrue. As for Venice: Are you judging a nation that had hundreds of years of history and was formed in the late 7th century by just one event in a military campaign?
That doesn't have much to do with anything else here, though.
Western Europe as a whole still progressed much slower compared to the Islamic world, China and India at that time, and the fact that Mongols and Manchus were behind China not advancing.