Since it's a research paper that you "wrote" (that is,
past tense), these suggestions (both mine and other respondent's) can't help you with your submission, but just remember that when writing papers, you have to remember who your audience is. Your audience here appears to be your teacher.
I hope that he/she is familiar with how to solve the Rubik's cube, because when you mention "The cuber will first solve the edges of the D-layer,", you don't define (or provide a picture of) what the different layers of the cube are. So you leave your reader
in the dark on page 3 (if not earlier) with just that fact alone. Don't misunderstand me, every teacher is different and has a different grading critique. And if he/she really doesn't
care about the little details more than the overall appearance of the work, that also helps. So if you didn't get your grade back yet, don't let my comment get you worried!
Instead I will congratulate you because it was quite brave of you to post a paper like that here. Because a lot of the points you made -- and even your quotes/support of your claims -- are subjective (even if you were led to believe otherwise with your interpretation of the sources you cited!), especially in the eyes of some of the people here (who have been around or have lurked around long enough to know that), since there are
so many exceptions to the rule.
I believe your paper is trying to put a finger on what that
rule is, but when one actually sees
maps of MANY methods and substeps and how they are connected, one can assume that the
rule for the optimal method is . . . is that
there are no rules, because there is no bound on how many algorithms someone can remember, the turn quality of cubes keeps increasing, the quantity of good tutorials keeps growing, and the ages of cubers who are getting access to those resources are getting younger. Well, okay, the last point has been around for at least a decade. But the
quantity of really young cubers is increasing (which means a larger variety of cool things can happen).
And, that being the case, if someone was to write what could be an "indisputable" paper, that paper would probably be written as one which was an observation of long-term case studies to reflect the trends (or non-trends) of cubers' behavior from decade to decade or
cubing generation to cubing generation.
In short, the nature of the objective of your paper (in my opinion) is similar to the masses trying to figure out what is the key contributor to obesity (which they obviously STILL don't know . . . or maybe that statement in of itself is an illogical premise . . . that there are many causes of obesity . . .
just as there are many paths to being a fast speedcuber: the cube, the method, the genetic predisposition, the environment,
the family/friend support, the current non-cuber cube craze (e.g.
The Pursuit of Happiness film caused the 2006 craze, Google's front page in 2014, due to the 40th anniversary), etc.
They keep proposing one diet (Atkins, Keto, etc.) one generation, and then change their minds the next. Meanwhile some people get results with one diet, while others with another.