I am not aware of any studies showing impact of what you call "not really keywords". Even if there were, I would ignore them as you have to ask, "Do these words mean anything to your users?" I work in some verticals where when you use a term like "wiki" or "faq" people think I am either talking about some type of weaved basket or I just said they were overweight, respectively. I think it is good to start from a common lexicon, with words like "wiki" etc, but you still have to ask that initial question.
We went through this exercise about 2 years ago on a site as we wanted to setup an evergreen section for the top 40 keyword concepts. Each concept would have a single page that would contain an original article that was at least 1,000 words long, custom videos, images, etc.
We asked a similar question. Should we call the section (and folder in the URL) "wiki", or "encyclopedia" or "info", etc? We did not want to call it a "wiki" as we had experts editing and writing and it was not open to the public to edit, even though for the sake of organization and layout, it looked like a wiki and provided information like one. This is when we found out that our users were generally not as familiar with wikis and the comment with the weaved basket came out.
We did some keyword research and found that the word "help" made sense to users and also with the way Google looked at our topics when you used help in conjunction with the key terms we were trying to rank for. So we ended up using a URL that was domain.com/help/keyword-topic-of-article-slug.html It has worked pretty well for us and the traffic has followed. We have our daily blog content and ecommerce sections in separate folder. Makes it easy with GA and Search Console as we can look at each section easily and determine what is going on. This was key when we had some issues with organic traffic as once we noticed overall traffic changes, we drilled down into the sections, found the issues and fixed.
TL;DR - Find out what words make sense to your users and use those, ideally they would also be keywords that you are trying to rank for. After than, just follow best practices for URL guidelines.