Imo if you're going to be the only one who would use the instance it is not worth it. Instead look for an instance that lines up with your personal interests (maybe check out the db0 instance).
Content federation basically works on a subscription model so you will only see content from other instances if someonen your instance went out of their way to subscribe to it. Smaller instances suffer under this as they might not even see popular communities from other instances.
Same, the only thing talkings to the internet are my reverse proxy and the security cameras (only when viewing them from outside the local network, quite like what reolink does there)