[douche]

Official corruption was certainly a huge issue. I don't have it on hand, but I recall reading in one of Pamela Crossley's books a study on the staggering percentage of the Green Standard and Banner military units that carried dead men on their rolls, officers selling off land designated for the maintenance of the military to line their own pockets, and outright embezzlement of military equipment (like the decades-old gunpowder and concrete-filled shells mentioned in your link to the Yalu River article). To some extent, the potentially ruinous expense of training and educating a candidate for the imperial examinations was predicated on a certain level of winked-at "squeeze."

The Taiping Rebellion can't be discounted when looking at the inability of the Qing Empire to cope with Western gunboat diplomacy. Wikipedia lists it as possibly the third most bloody war in the history of mankind[1], and besides dragging on for fourteen years and devastating some of the most productive areas of China, the government nearly fell, and increasingly impoverished and ineffective Manchu banner military forces were phased out and replaced with more regional, semi-private local forces, outside the traditional chain of command, raised and led by men like Zeng Guofan, Li Hongzhan and Zou Zongtang. While these initial commanders were more or less loyal to the Qing government, it arguably started the slide towards warlordism.

[1]https://en.wikipedia.org/wiki/List_of_wars_by_death_toll

[meric]

Yes, exactly right, the corruption of Qing institutions led to ineffective governance and impoverished people, giving rise to the Taiping Civil War. In fact, the seeds of the 1911 revolution were planted when a retired soldier of the Taiping army told of his stories to the children in his village, one of whom was Sun Yat Sen[1], who was a leader of the revolution that finally overturned the Qing.

Chinese soldiers and chinese equipment, though outdated by the standards of the time, are perfectly capable of defeating European military, on the off chance when they were sufficiently organised[2][3]. The heroes of the late Qing Empire shone, because around them, their colleagues lie low in the depths of corruption and incompetence. It's like a game of Starcraft, even with a bigger army, and bigger economy, an inexperienced player making a couple of mistakes will lose the game quite easily to a more experienced one.

[1] https://en.wikipedia.org/wiki/Taiping_Rebellion#Affectness_o...

[2] https://en.wikipedia.org/wiki/Battle_of_Taku_Forts_(1859)

[3] https://en.wikipedia.org/wiki/Battle_of_Cầu_Giấy_(Paper_Brid...

For historical interest, during the high point of the Ming empire, junks achieved in battle, decisive victories over Portguese caravels armed with cannons[3][4].

[4] https://en.wikipedia.org/wiki/Battle_of_Tunmen

[5] https://en.wikipedia.org/wiki/Battle_of_Xicaowan