How does images work with federation? If 1m users on a big server look at my images that I posted on a small server, is that small server hit with that traffic? Or is all servers caching the image?

The poop-knife.

I actually find traefik rather nice to work with. I have a few Middleware chains set up, expose service using labels and add the chains to make sure I get the appropriate settings.

I would look at this https://youtu.be/uaixCKTaqY0 in regards to nginx proxy manager. It might not apply to you but worth knowing at least.