Looks good for me! If your group is public, then the latest posts you make on your group will appear on the latest thread on the main page (on the right). They work as attractors to get more people joining and can contribute to the overall dynamic of the movement.
Do you see a need to keep any of the information private? In that case we may want either to make the narratives category private (which I would find a pity) or have a separate one for private communication, if you feel you have this need.
We can of course also adapt the design/layout not to show the latest posts and show instead something different. This is however pretty conventional and I have the feeling it looks good. But I’m open to other suggestions
PS: As for Zoom, yes, sure, if you have a paid plan and are hosting the session go for it. Jitsi would be the free and open source software alternative, but I guess it’s still not working as well as Zoom, which is a commercial product - but also as far as I know quite good on the privacy side, and supporting end-to-end encryption.