Both called are named have the same meaning although we would usually not say "I am named..." we would say "My name is..." - We would say "I am called..." but not "My call is..." "Named as" and "Called as" do not mean the same as the above. To be called as - would be used in the sentence "he was called as chief witness", and to be named as would be used in the sentence "he was named as executor of the will". Hope this helps!

Called as and named as are wrong, the other two are the same. Called is more common than named although it essentially has the same meaning. Named as is used but not in the way you would probably think, we say things like 'Mr X has been named as the CEO of...', but in this sentence named doesn't refer to the person's name, rather the appointing of somebody to the role.

孤陋寡闻了，called as 第一次听说过。