I'm not sure what you mean by rigid, so a description (of the state as of a few years ago; there were IMO very ill-thought-through reforms and I'm unfamiliar with the state after; I finished high school in 2008):
Primary school is uniform everywhere in length and is pretty uniform in expectations of what is taught.
Junior high (that got removed by the reforms) was also uniform in length and pretty uniform in expectations; there was a standardized two-part test at the end of it. Some amount of variance would manifest at this stage, but it wasn't very large in my time and my experience (and thus it somewhat forced teachers to reasonably deal with some variance of interest; I'm not sure how well that worked in general, because I have a sample of size 1).
After junior high the pathways split into roughly 3: trade schools, "specialized high schools" and general high schools. (The difference between first two is that "specialized high schools" end with the end-of-general-high-school exam.) From what I know there's lots of variance in terms of expectations, depth of teaching in various areas, etc. in the first two (and it's somewhat opaque so that choosing one is not trivial). In general high schools there's a pretty rigid set of expectations around what one should know afterwards for each subject, but one gets to decide on subjects they will take the end-of-high-school exam on. So, in practice there's more freedom for teachers of subjects that will not get chosen by their students for the exam. My experience of HS was very nice and possibly very atypical, because the HS I went to is nonconformist in many ways.
On the topic of expectations around uniform behaviour and similar sillynesses, they are pretty strong to start with, and get less strong towards HS (with the confounder of junior HS being stereotypically the age when kids are most likely to confront authority). (I remember thinking that the expectation to sit and not pace while thinking was weird.)
The subjective parts are confounded by:
- me living in a large city,
- (apart from primary school) my parents helping me choose a reasonable school (and that not requiring me to move, because large city),
- my parents being, I think, very proactive about helping me do interesting things (which might have affected teachers' view of me? I don't really know enough to tell).
