What if the Marshall Plan had not been implemented? What would have happened to Europe? Would Communism be more widespread? More military dictatorships in Western Europe?
The modern view is that Western Europe had already been recovering before the Marshall Plan, specifically West Germany, France, and Belgium.
However, France and others had used the funds from the Plan for the preservation of colonies abroad. France in particular benefited off of the money, trying to keep Indochina. Without such aid, its not hard to imagine a quicker end to the independence war for the Vietnamese. If the United States refuses aid to France, it might provide such a downturn in relations that the AHer's wet-dream of a Ho Chi Minh Vietnam and US pseudo-alliance becomes somewhat possible (though not very likely).
Doubtful. Other countries did very well without any grants like this (Japan for example) so while the recovery MAY have taken longer it would still happen.
And there is little to suggest that not having this money would lead to countries becoming communist or ruled by a military dictatorship.
Even without the plan the US is not going to withdraw from western europe and just let the Soviets walk in and try to take over.
3. It's unlikely that no Marshall Plan means the Red Tide completely engulfs all of Europe, but there's the possibility that the consequences of trying to deal with devastated postwar economies are exactly the sorts of things that cause people to lose faith in incumbent governments and listen to groups like communists who preach an alternative.
Eurocommunism arises earlier, perhaps even the French Communists or other parties that are affiliated with Moscow at this time make a break with the Soviet line, seeking to court the support of a worried populace. If anything, down the road it will mean a stronger social democrat presence in these states (or weaker depending on how well it works out). Stronger socialist and communist parties in Europe are always a good way of diversifying and splitting the Communist world.