I’m very interested in the Theme and will try to get some support on this.
Our organisation is afraid of what you described quite well by
There is feature request going partly in the same direction Higher level of granularity for category & subcategory styling although the reason for asking is properly the same
I tried to tackle this by creating Traditional multi level hierarchy vs flat discourse hierarchy
In there I stated our fears/challenges
You will find some illustration there to support users to find their area in the forum easier than now as soon as you reach a critical number of subcategories, tags, etc.
Allowing graphical may be added to your mockup.
Saying this, may you want to use quickMockup what allows to update the mockup and upload here.
Introduction/guidance can be given through a introduce yourself Custom Wizard Plugin 🧙
This will be a core requirement but it needs to be ensured that topics a properly tagged. Unfortunately, not every user behaves perfectly so there has to be an auto-tagging feature, as discussed in Topic auto tagging and Set up structured tagging with tag groups and category tag restrictions.
In addition, a user must be able to subscribe to tag intersection, what is currently not possible, see How to watch a tag intersection
I’m searching for the same thing to avoid to get another application involved covering the project management part.
I started Replacing Slack by Discourse once what should be combined with Kanban Board
Last but not least are you aware of: