I think there are two things that are preventing you from understanding how Discogs wants to operate.
The first is the sorting of the releases into different categories (albums, compilations, singles/EPs, Misc, etc.). As purlieu said, there's some old code and criteria that are not the greatest that makes for some messy sorting sometimes. You're just going to have to accept that you cannot affect that. There have been tons of discussions about it, and nothing's going to be changed with it in the near term. However, you cannot (and should not) tag formats based on how you want to force the releases to category sort.
Which brings me to the second item. The format tagging. In your posts, you've cited a lot of things that don't matter to Discogs, like number of tracks, duration, music retailer categorization, etc. You have to ignore all the stuff that you yourself normally consider or think of when you try to tag releases as singles, EPs, or albums on Discogs. In fact,
the guidelines even say this: "Do not guess at or attempt to apply personal standards to these tags." In the guideline, the only thing that matters is, did the band/label/release refer to/designate it as a single or EP or album? If so, then you can use the tag. If not, then you can't. It's really that simple.
As for your poing about compilations, there are
special rules about the Compilation tag, and it can absolutely be used in conjunction with other tags (it even says so first thing in the guideline: "The compilation tag can be used in conjunction with any other available tag, for example, 'Compilation, Album'"). So, for Drift Songs, it could, conceivable, qualify for both the Album and Compilation tags. However, we don't actually know yet, since we don't know what's going to be on the album. If it's all new songs, or different versions of the songs, it might not qualify for the Compilation tag.