Hey I can surely relate to Harry's opinion on the magical world. Hell anybody would be pissed if their entire life had been uprooted like his had by dumbydork! And as for his accord with voldie, I can see him doing that very easily. You dont bother me, then I want bother you, and you can have the magical world cause when my schooling is finished here at hogwarts I'm going back to the muggle world to live anyway.
P.S. I too have always figured that muggleborns would be long forgotten squib lines.