Yes, that is what I have been thinking might possibly explain AC6. There is indeed a statement by National Geographic about their goals for Geno 2.0, and one of them is that it is to trace the migration of the "Indo-Europeans". In the results from Geno 2.0, some of the Balkan countries do get higher values for what Geno 2.0 calls "Southwest Asian"...20 for Bulgaria, 18 for the Russians, 17 for Finns, Britain, Germany, Tuscany, etc, The only European countries of the ones listed that are very low for it are the Iberian countries, which only get 13. This might fit with the fact that the signal peters out as it goes west. It does look to me like a component that, once it got to Europe (in the Balkans), went overland in a more central Europe migration path, perhaps hitting Italy slightly later. I think this would fit in with the mtDNA results that just came out in the Brandt paper, which show a close FST between Eastern Europe and the northern Near East for mtDNA. How the H.Pamjav et al paper on the yDNA in Europe, which seems to show something similar for central East Europe fits in with all of this, I'm not sure. This is all just speculation, mind you! :)
http://en.wikipedia.org/wiki/Genographic_Project
http://www.dienekes.blogspot.com/201...ributions.html
Your analysis makes sense to me for the ranking of the K7b "West Asian" component. Assuming just for the moment that the ranking for the North Europe component is correct, the reasons are more obscure. The only thing that I can think of is the fact that when Dienekes analyzed the K12b North Euro component, using the "one out" method, North Euro K12b appears to be over 60% Atlanto-Med, over 30% Gedrosia, and a sliver of Siberian. And then, of course, Atlanto Med in another deconstruction, turned out to be mostly "Caucasus".
http://dienekes.blogspot.com/2012/08...-k12b-and.html
As to AC4, their "North-Western European" component, which is, as you say, probably closer to North West Eurasian, it may be correlated with Atlantic-Baltic from K7b as you suggest. However, that also raises other issues, since the f(3) statistics for Atlantic-Baltic appear to be "younger", and thus it looks more admixed. It shows up as a combination of Southern, Caucasus_Gedrosia, and a sliver of Amerindian. If that is correct, this Caucasus_Gedrosia component may have actually come into Europe far earlier than the Bronze Age, although certainly the Bronze Age could have added to the signal.