Yes, ideally you‘d want to have a few large communties on each instance and not all topics with a single userbase on one. This not only decreases the load but also prevents scenarios in which a single admin starts to capsule their instance with a large userbase away from the federation.

I really like the default active sorting keeping discussions in older threads alive for longer. The comment sorting also makes it easier to join discussions later on :)

Just until someone starts vomiting in places other than the toilet. In many cases it‘s better to be invited than to be the host ^^

You might like, wefwef.app if you are used to Apollo for Reddit :) Apart from that several native apps seem to be in development

Definetly good advice! :) Thanks you for recommending discuss.tchncs.de