Depending on an apartment building's posted rules, these basic actions may be prohibited. Although thanks to modern building techniques and proper insulation, the gushing sound of sewage or shower water has become less of an issue these days. Although there is no particular paragraph in Swiss law restricting tenants from these things, the Swiss Homeowners' Society (HEV) leaves it open to the owner to set those rules.
Article 257f of the Swiss renters' law (OR) contains some generic language about considering others. It states that a tenant must be mindful of other tenants and neighbors, so draining a bathtub after 10 PM might be considered borderline...