The second one could probably be achieved with 3rd party tools already. The best one I can think of would be IFTTT. Each category has an RSS feed, therefore if RSS feed gets updated. Send email. Full IFTTT support would be great, I'm not sure how that would work, but being able to set up that sort of thing would be bloody brilliant. Maybe even baked into nodebb, so we can set up "tasks" similar to how stamplay.com works. Just with a betteR UI.
UNSOLVED Notifications with HTML
If you want to have HTML in notification body, you should use translations only?
Because, if you provide raw html, like this:
notificationObj.bodyShort = 'Some message <strong>important</strong>';
It will output html tags.
Can you submit an issue on GH for this?
We sanitize HTML on notifs for removing breaking HTML from stuff like post teasers. It really should just sanitize the values of the object passed into the rendering and not the resulting text as a whole.