I guess that only applies to paywalls that can also be bypassed by 12ft.io, right? I.e. paywalls that open themselves up for indexing by search engines like Bing or Google.

More people should move their accounts off to smaller instances with less load. You can still interact with communities the same way, but have a user experience that is a lot better.

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.