@irina
The problem I still see is that tagging and other such actions remain optional, which means people will ignore or simply forget about them. A good platform design would force adding metadata without making it feel like a chore. (Forcing people to add at least 1 hashtag will just lead to useless hashtags.)
It could be achieved by having something like communities as a feature, where people join them and send their posts to those communities rather than all followers. It would automatically make the post visible only to the selected audience so you wouldn't have to care about what happens "outside". (You can probably find flaws in this specific idea, but the point is the principle behind it)
@volpi@icy.wyvern.rip