Outsider Contributions: Are They Possible, and How?
Most of our audience here are academics and the OP is Not Quite An Outsider, I think I don't need to explain how important peer review is to research results. If the outsider needs the explanation, please use the peer-review to read related Q&amp;A.

Obviously, the outsider has at least two options: submit the manuscript to journals and/or having blog posts of his own.

One of the effective ways to get your paper to be peer reviewed is to send the paper to journals. It is true that some journals tend to ignore papers written by authors without affiliation. I personally have this experience. I am retired and am not associated with any institute. I do have experience that my manuscript was rejected without any explanation. However, the quality of the paper makes the difference. If it is indeed a very good paper, some journals would take it and send to referees. I personally have that experience, too.

The second option for an outsider is to have blog posts. I occasionally come cross blog posts when I search on the Internet (I am a retiree, I have plenty of time). My personal experience is that more than often good blogs are written by good scholars who are insiders. I bumped into many poor quality stuff written by outsiders quite often. They just don't make sense to me at all. I usually read the first couple of paragraphs to determine if I want to continue to read them. Unfortunately, most of them written by outsiders are of extremely poor quality.

Of course, the outsider has another option - arXiv. I think it does not make too much difference with regard to your question.

To me, the key issue is the contents. If you do have something very good, publish it. Somehow, somewhere, your article will be read by others. However, if you never receive college education, I seriously doubt your stuff is good. You do need at least basic level knowledge to do research.