1. Almost every instance will almost certainly filter illegal content in their respective jurisdictions, and those that don’t might not be around for long.
2. There is a modlog. Just click on it, and you will see what gets removed.

This is where the transparency that comes with FOSS vs private corp really shines. You can always check an instance’s modlog to see for yourself where lines are drawn.

BeeHaw will supposedly censor what they deem to be “hate speech”

I’ve heard reports about lemmy.ml censoring criticism of the CCP. how true this is i don’t know. One of the devs apparently also runs Lemmygrad