Concerning Czechoslovakia, what I find so intriguing is that there were no Soviet occupation troops to enforce full communization from December 1945 on, and also President Benes was, I believe, a respected figure. The conditions for escaping a communist outcome were better in Czechoslovakia than anywhere else in eastern Europe, but alas it was not to be.
Entering Czechoslovakia
en force is not such a hard job. Germans did it in 1938, Russians did it in 1968. They had been allocated to the Soviet Zone - and that was, unfortunately, it.
The reason "Finlandization" was possible is that they had a certain respected gentleman, called Carl Gustav Mannerheim there. And that gentleman was known for administering a major bloodletting to the Russians 3 times in the previous 25 years or so. They knew, they could, probably, impose their designs on Finland in 1945 - but that would have meant, actually, fighting another war. In 1945 Finns would have lost, of course - but they would have killed a lot of Russians in the process. And once they would have started fighting, the Brits and the rest would have been hard-pressed not to support them, at least in supplies. Stalin was not ready for another hot war just yet.
Czechs, on the other hand, do not fight, nor was Benes a Mannherheim - and Stalin knew that. Their only chance was finding themselves, at least partially, in a US occupation zone. They didnīt have the luck. Benes was used to sanctify expulsion of the Germans. After that his usefulness was over.