Pretty much everybody will work by the working regulations - in my case typically CS.23 or CS25, EASA-FCL and then next layer interpretative materials such as the CS.23 AMCs, or UK's CAP 804. Virtually nobody goes up a layer to the encompassing regulations as they're largely irrelevant to most of us and we usually don't even know their names and definitions - and it's those regulations which you've listed.
Incidentally where in my opinion EASA most falls down is not on publishing and making accessible the regulations, but the explanations of how to use your application. I know my way around CS.23 extremely well and have no trouble constructing a technical case using it, but have at best a vague idea of the route by which I make a design application to EASA which includes that technical case.
G