wow… im impressed! 
i love your systematic approach to the subject. i understand where you are coming from with this approach, and it makes a lot of sense to start study in this way.
i think the reason why many sources recommend to study the opening is that it is helpful (and comforting) for beginners to have something to start with. actually playing a 19x19 game can be frightening to beginners. especially on an empty board the possibilities often seem endless!
the way to go about this, imo, is not to memorise a move-order, but to focus on the stones relation to each other. (i.e. how to enclose a corner, when to play a two space jump, when to ask for more…)
similarly (for the sake of thouroughness, i am actually not a great advocate of joseki-study) the way to understand the joseki study-recommendation is not to make all beginners memorise the patterns and leave it at that. rather what is usually meant, is to learn from joseki. joseki are optimised move orders, which have been subject of in depth study for (sometimes) centuries. each move has a purpose, an underlying tesuji for example. joseki teach about shape, shape points, urgency, sente and more . of course a random board position likely offers that too, but where to find the explanation?
because corner-play repeats most reliably every few games, we can use joseki to teach and explain moves and shapes, why they are good/effective and then try to spot similar situations in later stages of the game and other parts of the board.
shape, stone development and the relation of stones with each other is also probably the only major topic i couldnt find on your list, although partially covered by “how to create frameworks”, “how to battle locally” and “how to link your scattered pieces”.