As Ruy Horta wrote - the main subject of this topic was if Pe-2 or its roots VI-100 was a copy of Bf-110. And as many people wrote - it wasn't. It was very similar in designing idea but it was not a copy - in technical meaning of this word (as Tu-4 was for example). Panther wasn't a copy of T-34, Su-9 wasn't a copy of Schwalbe...
I think there is no need to arguee about the influence of western technology on Soviet aviation industry. Becouse it's obvious and well known. Most of soviet aviational engines were copies or developed copies (built on license or not) of French, British or German ones...
There is a very interesting book about German technologies in VVS service:
http://www.armybook.com/summary.html?code=0101007i35