As far as delineating between a question and a discussion visually, how about something like a watermark inside the text space of the original post? It could be a bit more visually interesting than a plain question mark or other symbol for discussion, such as a bevel in it or a slightly 3D outline to it. A symbol to use for discussions could be the exclamation point or asterisk. Additionally, it could be color-coded in terms of the overlaid posting space (e.g., currently it’s a lighter dark grey background overlaid on a nearly black dark grey background).
One of the main problems I see with merging Q&A / AnswerHub into the forums is the sheer volume of posts to contend with for users, especially beginners and users who are new to the forums or rarely / occasionally access them.
Another issue that is potentially avoidable is a rating / voting function which causes certain answers and solutions that are voted higher to supercede other ones and causes a rift in which people for whom those ‘best’ answers don’t work are going to be digging deeper and deeper into the forums to discover the ancient artifacts that resolve their modern dilemma. IMO, and as a suggestion from considering the causality, it would be better to divvy up the workload of accessing information / answers in a Q&A section by making it an option to enable or disable the influence of the voting system. This is already an issue in the forums wherein a question is asked or a problem posted to ask for help, and the OP is having to decide among a number of answers and potential solutions. The decisive factor is not always, nor should it be leveraged in a forum or a deep Q&A as, the popularity level of the answer / solution / reply. The idea stated above to improve forum efficiency and avoid redundancies more by creating an FAQ and common problems / mistakes and their solutions is workable for the whole knowledge base, and there probably needs to be direct links to those pages or that subsection of the site somewhere in forums that is easily accessible for new users. And not relegated to the top of the hub of the forums, but perhaps at the bottom with the suggested / latest posts area too. I’d say put it in a sidenav, but there’s nothing of the sort currently in the forums and I don’t know if Discourse would support that feature. It might also be unwelcome or an annoyance to numerous users to see it on the side, and have to scroll to it to click such a link during the searching of a long series of topic replies. So, another idea for linking to other learning / FAQ pages, contextually based on the topic / question, is another icon or text link inside each posting or reply (e.g., next to the heart, share-a-link, flag, etc).