Wang Anshi's reforms may have saved a lot of money to allow Song to build a large army, bigger than its predecessor. However, Song's large bureaucracy was unable to adjust to its new policies. With constant, unnecessary campaign to annex Dai Viet in 1075 which lasted until 1077, follow by the invasion of Tangut, it destroyed much of their regular well trained army force. The cost of war was more than what Song Shenzong have to spend. This nearly bankrupted Northern Song causing it to grow weaker.
The military reforms allowed low ranking civilians of the scholar-gentry to run the army made up of ill-trained militias, plus training of military horses were left in the care and responsibility of farmers. By 1126, Song army was weakened to extent. This left the dynasty vulnerable to nomadic invasion on the frontiers. Subsequently forcing Song Prince to flee south across the Yangtze River to Hongzhou to established Southern Song.
You don't seem top realize you contradict yourself the reforms themselves are not the problems its the emperor in charge who ordered the invasion of Dai Viet and XiXia.
You argued that the Song was bankrupt from the Baojia system when in fact the policies resulted in a surplus,which emboldened Song Shenzong to preform military actions against his enemies.
Northern Song didn't fall because of the Baojia system it fell because a combination of factors including:
1. Factional strife ie Cai Qing purging officials that didn't agree with him as well as monopolizing power,
3.Reckless interpretation of the new reforms ie Cai Qing went farther than any of the previous reformers effectively turning the system into extortion and strangling merchants. However this cash was mainly diverted into the lining the pockets of the corrupt government officials as well as the Imperial family. However social welfare and training the extended Zhao clan also sapped the treasury.
4.Song Huizong was too steeped in superstition and proceeded to build expensive projects to rectify the balance of the universe therefore causing rebellions as well as wasting troops to guard his treasure fleets. Song Huizong was also a megalomaniac in an effort to show his superiority he gave state cash to Taoist temples further diluting the funds.
5.The Baojia troops were busy fighting internal wars ie Fang La rebellions as well as the Khitans and Jurchens,the issue isn't about troops quality but the councilors and generals who commanded them.
Even thought the invasions against XiXia costed astronomical amounts of money,the troops succeeded in repelling and for a while held XiXia by its throat. The issue was that the generals had no goal just throwing resources and men away while a incompetent eunuch resulted in 200,000 imperial Song troops dying.
Even though Fang La and Song Jiang's rebellions were crushed the court did the exact same thing they were doing before extracting resources and overtaxing peasants.
The issue with the Jurchens is that the Song army veterans were squandered in pacifying rebellions as well as the fruitless invasion of XiXia.
Gobi desert and Takla Makan desert prevented Afanasievo culture from crossing to the central plain.
Camels were introduce to China during Tang Dynasty.
Erlitou culture is Shang and Zhou Dynasty.
There are many published articles and books regarding Neolithic Bronze Age. Below are two sources. You may Google them for yourself.
The Archaeology of Ancient China (4th edition), by K.C. Chang (Yale, 1987).
NEOLITHIC CHINA: BEFORE THE SHANG DYNASTY; Indiana university
To prove who invited what first does not matter much to most people. We are all living in the same age with the same technology readily available. The only difference between households, are cost of living, family, friends, liberty, and job security. These are what matters to all people. One can only achieve this living conditions in a free government with the ability to check and sustain the balance of power between the people and itself.
No ,the Shang definitely had contact with the Afanasievo cultures,sacrificial victims included Caucasoid skulls as well as the introduction of chariots and horses.
Erlitou =/= Shang or the Zhou,neither Erlitou or Erligang left behind traces of writing so how can they be equivalent to the Shang or the Zhou?
NEOLITHIC CHINA: BEFORE THE SHANG DYNASTY doesn't say where the bronze originates.
The Shang colonized Wancheng as well as Panlongcheng therefore the bronzes there resemble Shang ones,however other sites such as Sanxingdui exhibit a completely different tradition because the Shang did not interact with them.
If you're going to argue that Shang bronzes originated from the south than you have to explain why Shang didn't have southern bronzes such as bells.
Wucheng and Shang:A New History of a Bronze Age Civilization in Southern China by Zhang Liangren