5. This is a personal preference which is why i think people refer to the grower as things that effect yields since its how you setup the plant to grow itself. Trying new things will often put growers in the position of learning all over again even experienced growers may experience lower yields.
All growers are different some don't care about energy usage and some need to be stealth, I think the most major thing to determine yields in being able to adapt plants into the microenviorment and being able to read what it needs(nutes, water or training).
1) temperature - dont believe it? grow at 40* or so
1) light - it's really a tie (try growing in the dark?)
2) moisture level of medium
2) nutrient regimen (also a tie)
3) training
first is genetics
second is light
third is air(both in the room and in the medium) lets face it medium is just a word for air n water holder.
4th is water, this is a close tie with air as one dont work without the other, but great water and no air is less important then excellent air levels n decent water pureity.
5th is nutes..,
well, strain aside, with growing conditions a person will get some or none.
OIW, w/ the 5 points i mentioned done proper (within margins) then, of course, a more heavily yielding strain will yield more heavily than a poorly yielding strain.