If Putin thinks that the greatest tragedy of his time is the fall of the Soviet union, no amount of "safe space" and "buffer zone" is going to satisfy him until he has the entire Warsaw pact under Russia's heel. Economics is how people live and prosper, I don't see how it's any less important than security concerns.
You clearly do not understand what he was talking about when he made that statement. And it does not take a genius to look at the demographic statistics of the Soviet Union after the collapse, statistics for things like unemployment, death rate, and life expectancy, or alcoholism to realize the Soviet collapse was worse in demographic terms than the Russian Civil War.
With regards to NATO enlargement, he said as much in the Munich Security Conference in 2007, that either NATO kept to the principles of the Conventional Forces in Europe Treaty, or that Russia would have to rearm itself. NATO had plenty of time to do a deal to reduce the amount of conventional forces in Europe. Instead they publicly announced the intent for Georgia and Ukraine to join NATO. The Russians have said since the US announced they would be accepting the Baltics into NATO that accepting ex-USSR republics into NATO was a red line. The US did not listen.