My search-fu wasn’t at its best yesterday, it seems.
This thread raises, among other things, the same issue as me concerning that sections need to have predetermined names for themes to work.
@CREwert asks what the users of themes should expect sections to be named. I, on my end, am asking what I should expect users to expect my theme to require.
For now, I think I’ll go with soft linked folders named blog, post and posts under layout for the blog, and likewise for the four versions of archives I listed.
I noticed that my theme broke when I defined taxonomies in the plural in the site config, since I had used the singular in a template. Here, at least, I think I will only have to check for “tag” and “tags” and it should be covered.