Quite, and they have to be addressed in sequence. One cannot discuss responsibility without discussing awareness first.
Since the end of the war, the line of the of the clean Wehrmacht had been that it had no involvement. Killings were done by others, soldiers were not aware of them. An eloquent testimony to this line is the questioning of von Manstein at Nuremberg. http://www.yale.edu/lawweb/avalon/imt/proc/08-10-46.htm
To me, the evidence the transcripts present, as well as the extant documentation, shatter this defense. The absolute idea of a clean Wehrmacht can no longer be honestly supported, in my view. It is clear that within the Wehrmacht knowledge existed, that it was reasonably widespread at the higher levels of command, and that parts of the Wehrmacht, for whatever reason, contributed to the criminal activities of the regime. That is my opinion, based on the evidence already presented here.
Before we can move on to discuss responsibility, either as a group or as individuals, this needs to be hashed out. Because otherwise the responsibility question goes by default for those who disagree with my view. No knowledge equals no responsibility. Note that it does not work the other way round, for me. Some knowledge does not equal responsibility.
So my clear preference is to first see if we can actually agree that knowledge existed, and debate the extent of it. Responsibility, either as a group, or on the personal level, is another question, that can not really be addressed before the first one has been settled.
All the best