Yes, the Russians, due to their almost ancient territorial paranoia, do have security concerns. It would be helpful for peace, if they could be reassured somehow.
  However, it is difficult to view the reoccupation of several FORMER USSR states, other than this age old paranoia coming into play in an act of aggression.
  Yes, Putin believes that the breakup of the old USSR is the single greatest tragedy since WW2, but it seems he would be a better leader if he would just "suck it up", and move on to do some very worthwhile things with what he has left to work with..
  So far as any Nazi party if it exists at all, must be a small splinter group, much like the half-baked Nazis here 
    in the US, since I cannot see any form of major support for anything Nazi, especially in Europe.
  I am not ascribing any "pure as the driven snow", character to the Ukraine government, but as any major 
    movement, I have serious doubts that Naziism can gain any traction whatsoever.
  Since the link you offered, the SOTT website, delves into minute historic details of the Russian federation, back into medieval times, it has the earmarks of being a Russian inspired  website.