Say, could have Tokugawa period witnessed more turbulence then it did IOTL ?
I know little about Tokugawa Period of Japan, but it sometimes amazes me seeing how long the Shogunate kept peace and stability over entire Japan not only from disunity, but also from the internal problems within the Shogunal family itself. A stern conservatism that endured for 2 and a half centuries straight that prevented any meaningful evolution of the nature of the regime, as well as any unfortunate event that could've brought it down and potentially put an end to peace in Japan.
However, is it true that there wasn't any point during that timespan which could've developed into something dangerously big that could've threaten their hold onto power ? That, if it won't bring the Shogunate down, at least force her to evolve and perhaps reconsider her previous position on issues ?
Basically I just want to see if Tokugawa system had any crack that could've expanded any time. I'm interested in the possibility of Tokugawa regime either falling or reforming earlier, from internal cause. Indeed, by the coming of Matthew Perry, it was already spoiling. But honestly, I do seek to achieve an earlier end to Sakoku after Iemitsu, through a different way, and see where it will end up.
I am also interested in a Japan that simply develops under a different system from what the Tokugawa espoused in our world. An actual Satsuma Shogunate, perhaps, that would be more active in foreign trade and more relaxed attitude about movement of people between Japan and outside world (I can be wrong in the way I judge Satsuma here, so correct me if so). Or instead the other way around, a heavier centralization after a brief turbulence that ends with Tokugawa's direct possession of any of the four "gateways", especially Satsuma and Dejima, that would in time, encourage gradual shift of stand over isolationism. Or perhaps, simply another period of divided Japan in the period where European intervention is a less pressing threat, at least until the dawn of Industrial Revolution.