I am assuming that your latest canonical question was closed as "opinion-based" because it was perceived as misleading and incorrect.
Until you're willing to remove/edit the statement regarding Fraternities, or at least try to defend it and actually say that it is actually correct, I'm not sure it's worth working on those other issues.
The Fraternity Paradox: Lower GPA, Higher Incomes.
Greek Fraternities do not have Lower GPA averages, they have higher average GPAs than the average student population (because they kick out any brother who has a low GPA, but that's beside the point).
According to Stephen Schmidt and Lewis Davis, two economists at Union
College who (along with Jack Mara, class of 2010, whose undergraduate
thesis became the basis for the paper) studied the effects of
fraternity membership at a Northeastern liberal arts college,
“fraternity membership lower[ed] student GPA by approximately 0.25
points on the traditional four-point scale, but rais[ed] future income
by approximately 36%.”
If you carefully read between the lines of the study quoted in the news article, you'll see that the people who authored that study actually chose their words very carefully, and that they must have known that Greek Fraternities on average have higher GPAs than the overall student population, but that the entire news article does everything it can to imply the opposite through careful ambiguous quoting the study's findings and through its purposefully very misleading click-bait headline.
As to writing canonical questions, I don't think it's an easy task. I've never done it myself.
Usually, it's someone who is tired of answering the same type of question over and over again. So then he posts a canonical question and then immediately posts a comprehensive answer that he has already prepared in advance.
In your case, that's not what happened, you've posted all your research upfront within the question itself. Furthermore, your own research doesn't seem to satisfy the criterion of "fact-based" definitiveness you try to impose on the rest of us, as it's linking to a distorted secondary source with an agenda and a tertiary source found on a political website. Although, I do really like the personal experiment posted by Paul Butler on his blog. You should definitely keep that one.
To be more effective, you should give us a chance to vote on your question and answer separately and also refine your comprehensive answer. And you should link to the original studies or experiments when you can. And if someone thinks they can do better than your canonical answer, that person will jump in, but until then, I think you should work on your own comprehensive answer and continue to refine it.