This is mostly baloney.
Europeans used guns because they were better missile weapons than bows; their superior range, accuracy, armor penetration, and killing power more than made of for their slower rate of fire. Even soldiers who had trained to use bows shot better when they switched to guns. Moreover, firearms were considered weapons for highly trained troops, not masses of peasants. On the other hand, the bow was considered a 'natural weapon' that didn't need much teaching to use to some level of effectiveness. Supposedly, the French effort to train a corps of native longbowmen was scotched because they became too good too fast, and it was feared they would undermine the manorial order.
Not really. When you break down the lists, a lot of the 'cannon' are just oversized muskets; looking at the weight of shot their armies were capable of throwing, European armies were well ahead of the Chinese by 1700. Moreover, their guns were generally better designed, having a better ratio of shot : barrel weight.
This is beside the point; star fortresses only developed because gunpowder had already turned into a wall-smashing weapon in Europe in the late 14th century. The theory is that this happened because the walls of the 14th century Europe were small enough to be feasibly smashed by contemporary cannon, thus facilitating this development. By contrast, Chinese walls were ridiculously huge, so the potential of gunpowder to breach them may not have been apparent.