I reckon one reason why the MC is getting seemingly weaker, aside from not practicing/cultivating anymore, is because he's getting embroiled in complicated politics, shady business, and lots of conflicting interests in general. If it becomes difficult to see clearly where your own benefit lies in all of it and, on the other hand, even more difficult to predict actions that hurt your case, it can very easily lead to being passive. It most certainly won't help the dude can't keep his pants on and must chase multiple women at the same time, with some of them women even working for different, competing groups to boot.
@Valve China has quite strict gun legislation, so it's no wonder regular people know little about them. Unless you are a hunter, you will not see a gun outside of certain work environments (cops, military, armed security, etc). It's the same as in Japan, and it for sure shows in the fiction from those countries.