That's a strawman argument and an argument from emotion. If they're really hosting CP, then bring down the law on them. They usually can't because they likely aren't hosting CP, they're hosting content that makes you uncomfortable. I'm not for banning stuff that makes you uncomfortable, regardless of how extreme it is. Defederating just means separation, it effectively does nothing to the content itself except make it very slightly harder to access.
I agree actually. Everything is already super fragmented ultimately defeating the purpose of federation. Defederating doesn't remove that content either, it just makes it harder to access.
The magic here is that it can't happen. People can just start their own instance up and it's all open source.
Same. Choose an instance, sign up. You don't really need to understand the federation stuff (although it helps understand the quirks).