Terminology's going to get in the way here. Can you edit the above, so it's clear when you're meaning:
- A primary source in the sense of "a personal or eye witness account, or the original writing" - one which represents the words of its author alone.
- A writing as above, but from a source usually recognized to be reliable despite no formal peer review (government and certain major organizations' official/formal records, etc)
- A source such as a peer reviewed paper that represents the view of its author but has some kind of credible review
- A source where an author discusses and analyzes various of the above dispassionately, to provide coverage of a topic.
I numbered your four types and put red numbers in my last reply. A star means "part of type ...". I feel we should find better terminology/definitions first if we want to continue this discussion. But do we? Our task force could for example end up giving advice on the creation of wizards/guidelines for every source type we can identify ('when to cite a peer-reviewed paper about history'). I'm not sure if this discussion leads to one of the 2-4 most effective recommendations this task force could give for improving quality though.
Often seemingly self-evident primary sources are not reliable. In fact very often the converse is the case. They are explicitly unreliable, erroneous, biased, slanted, POV or downright lies and propaganda. Even basic level history students are taught that in evaluating evidence one has to be critical of its provenance, its intention and the careful handling of all such testimony as corroboration. The current obsession with citing sources has led to rafts and reams of citations which fulfill policy criteria at the marked expense of quality.
That was exactly the point I tried to make in the other thread at this talk page. The use of primary sources should be discouraged when the contributor doesn't have extensive knowledge about a subject. In practice, that means only specialist users should be using primary sources. Other users should be actively discouraged to do so.