Federated means that any instance that is federated with them receives their content and can bee seen on that instance.
Defederated means they are not federated anymore, thus blocking both users and content.
It’s usually done to combat content you don’t want on your instance
I hardly think it is necessary to be an expert in Near-East conflict or politics in order to condemn what basically amounts to a terrorist attack.
Whether or not they should do something is a different issue all together. But dismissing criticism because they don’t provide an alternate solution to an intricate problem is hardly any more helpful. Israel has many more pathways to do this properly, one idea would be the ICJ.
You’re also falling into an overgeneralization fallacy. While Hezbollah is in the lebanese government, this doesn’t make all citizens of lebanon complicit. Hezbollah doesn’t represent all of Lebanon, neither do Hamas all of Palestine or Netanjahu all of Israel.