Just because Russia is guilty of some things, does not mean that they are automatically guilty of others.
> nothing to do with with Litvinenko's murder
Probably the Russian government was involved.
> Nemtsov's murder,
Nothing has been proven, it is just pure speculation. I really don't think the government benefited by killing him on red square -- it created a huge embarrassment.
> Shooting down MH-17,
Russia may have provided assistance to rebels (e.g. in the form of air defense). But there is no proof at all that a civilian plane was shot down on purpose on orders of the Russian government. In most probability it is a tragic accident (as happened earlier: https://en.wikipedia.org/wiki/Siberia_Airlines_Flight_1812). These accidents are bound to happen when civilian planes fly over warzones.
> comment about Stalin (Russians always did adore their Tyrants),
Russians have a complex and tragic history. It is not that easy to reject all of your history (the good and the bad).
I wonder if you are equally vocal about neighbouring countries who still adore their Nazi independence fighters...