I have a question about Flow "workflows". From what I understood, a "workflow" is some facility which eases conducting a specific type of discussion, hardcoded into Flow for each specific use case. Which strikes me as inflexible and impractical. Say we have a deletion workflow. If for some reason the deletion process needs to be changed, this would entail a need to change in software. And we all know that changes to software are slow and painful. The same would apply if for some reason we needed to have a new workflow created.
Meanwhile, on Wikia, I see there are "forums" with a really neat feature: threads attached to ordinary pages. I would do something like that: each Flow thread would have a list of one or more pages it relates to. A "User" discussion would be nothing more than a discussion attached to a user page. A "deletion discussion" would be nothing more than a discussion attached to the page under consideration and a deletion policy page in the project namespace, or even some specially designated page to which deletion discussions are attached. A "newbie asks for help" discussion would be simply attached to both the user's page and the "active newbie requests" page. There would be no need to distinguish "User talk" from other types of discussions at all. Simple, flexible, and integrates neatly with wiki structure.
[Edit: I read a reply below indicating this is pretty much exactly what is planned. Never mind. But then, what are workflows, actually?]
Some time ago on w:WP:VPT I also proposed a "page tagging" feature, for tags like "unreferenced". Talk page banners could be integrated into that. If we wrote such a thing, it could eliminate the need for an "unstructured heading" space too, further simplifying things.