Hi Justin,
On the face of it a very simple set of questions and as we all know with one simple Yes to each question. Alas the answer the writer is searching for has been placed on the forbidden list by a lot of well-meaning but ultimately fatal books, articles methods and singers and pupils of singers. The answer is The Old Italian School which used the ear as the primary organ for saying what was good, bad or incorrect, coupled with a perfect attack (coup de glotte), and correct breathing from the diaphragm.
Unfortunately the scientists got in on the act and made everything so complicated that no singer could use the natural, methods, “false” singing methods sprang up purporting to follow X,Y or Z who had proved scientifically that if you place your throat so and your face so then you will be a perfect singer. Nature intended that we only imagine the note and sound we desire and it does the rest, assuming we are in command of the “right” method. To show scientifically how that happens only confuses the whole picture as words cannot fully describe what happens inside the head and chest of the singer. The result is that science proved the natural way was also the most dangerous so it was banned, but as we all know if you begin a scientific research project with faulty data and parameters then you will arrive at a wrong conclusion. That has happened with singing. Perhaps we should let the ear decide and not a scientific researcher what the answers should be to the questions posed above.