Van,
You have a very good grasp of some of the facts, but are also ignoring key aspects of the Yalta agreement, and of Stalin's failure to honour the commitments he made to the USA and UK.
The Russian view of Yalta was that she recognised and respected the agreed spheres of influence, stuck to the agreed occupation zones in Germany and Austria and left Greece and Turkey well alone.
I believe that Stalin probably assumed that all the stuff in the Yalta agreement about establishing democracies in the former occupied nations and axis allies was irrelevant hot air and window dressing purely intended for public consumption in the USA and UK. I suspect that he genuinely believed that Russia would be left alone to run its sphere of influence exactly as it saw fit. Perhaps he was encouraged in this belief by the supine return of the Cossacks who had fought on the German side?
But the Western Powers believed that the provisions of the Yalta agreement guaranteeing free and fair elections in all liberated European and former Axis satellite countries would be honoured, and viewed it as being of paramount importance. The Allies agreed to recognise the pro-Soviet
Lublin government in the short-term, but only with the proviso that it should be "reorganized on a broader democratic basis with the inclusion of democratic leaders from Poland and from Poles abroad."
It should be obvious to anyone that Stalin failed to live up to his side of the bargain on this!
Having gone to war to try to save Poland from domination by one totalitarian dictatorship, it was never likely that the UK and France would happily see Poland dominated by another one.
It was Stalin's unwillingness to implement this free and democratic aspect of Yalta that led directly to the Cold War, and ultimately to the defeat and collapse of the USSR.