Do all sentences make sense and essentially mean the same thing? Native English speakers please help?

They are all correct but the first one means GUILTY, culpable 2. , and 3. Are synonyms.

1 He cannot legally be held blameworthy for something bad that has happened. 2 Sorry, don't know 3 He cannot be considerd 'responsible' from a legal standpoint because he is either under age or certifiably not of sound mind. It is simply stating his legal status - he may not have done anything wrong.

The three do assert essentially the same thing. The context is missing. Context is key to understanding.

Yes, all are natural, correct, and equivalent.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.