A fixed wheel counts as a brake, though I've only seen the law in relation to bicycles which require 2 working brakes not sure how this applied to unicycles.
The increasing prevalence of non-standard evaluation in R packages was one of the major reasons I switched from R to python for my work. The amount of ceremony and constant API changes just to have something as an argument in a function drove me mad.
I'm not sure which European country you're thinking about, but we had lockers, individual backpacks and heavy textbooks. I never used my locker because we didn't have enough time between lessons, so I just carried all my heavy textbooks for the day as did most people.