Yes, it was exporting grain to get required currency.Not quite: at the time a famine was occurring in the Ukraine, the USSR was actually exporting grain to pay for its industrialization program.
As soon as the scale of famine become known, the export was seriously cut and food aid was given to suffered regions.
Yes, really - and you might want to check some actual sources on that. I like your argument, sounds very strong.Really? You might want to check some actual sources on that.
What you would propose, great general - to put all forces in Siberia?Seeing as the greater part of those frontier forces got eliminated in the first few days of the war, I rest my case.
So, is my number a "huge underestimate", or it is "on the lower side of estimates", according to your wiki source?I'm not sure where you checked, but since a lot of Soviet archives have been opened it is verifiable that your 4% number is a huge underestimate. But, let's for arguments sake, assume for a moment even that low figure is correct. Then after the first few months of the Axis offensive, the remaining officer would be further reduced by 50%, since the Red Army lost about half of its existing forces (including the commanding officers, such as there were) during that offensive.
So your 4% would be on the lower side of estimates. However, as you can see in the first paragraph, top ranking officers (i.e commanding officers) were hit hardest - and many were sumply executed, so 'reinstatement' would not really be an option for those.

What percentage of their land forces were in those fronts? And how it is compared to years of fighting on Western front of WW1?Actually, by 1941, the Axis faced three fronts: the ongoing airwar with Britain, the North African front and the Eastern front. (To even begin Operation Barbarossa, Germany had to withdraw a considerbale amount of its airforce from the West to the East.)
I guess the fact that USSR was recognized by several capitalist states, and had diplomatic negotiations with them, make it perfectly safe from any further aggression.In the 1930s the USSR gained recognition by several capitalist states. If your hypothesis that the whole industrialization had as its goal rearmament is correct, that makes the 1930s army purges nonsensical (and utterly counterproductive). In fact, until the Nazi frontline along its Western borders, the USSR did not face any serious threat to its existence. Such conflicts as there were, were decided in the USSR's favour (border conflicts with Japan, Winter War with Finland). Directly prior to WW II there had been diplomatic negotiations with all European powers, before Stalin setled on the Ribbentrop pact with Nazi Germany.
Well, I would like to listen to your explanation of the real reasons behind industrialization and purges. If it was not a preparation for war (nobody threatened USSR), and not destroying the internal opposition and consolidation of power, then what makes them sensible and productive?In the 1930s the USSR gained recognition by several capitalist states. If your hypothesis that the whole industrialization had as its goal rearmament is correct, that makes the 1930s army purges nonsensical (and utterly counterproductive).