First of all we're talking about a what-if scenario, where the US didnt enter the war in europe, so Stalin couldnt have been planning a war against them, because they werent anywhere he could reach.
Stalin had good reason to plan for a war against the US in the fifties, the US at the time was violently anti-communist with the McCarthney purges in full swing and the Korean war fought in the start of the decade. I seriously doubt he actually intended to start one though, whatever else about him he wasnt stupid and considering the US came through ww2 relativly unscathed while Russia was devestated it would have been a particularly stupid thing to do.
Stalin didnt give a **** how many Russians he killed, he did give a **** about how many somebody else killed. And they werent just numerical casualties, 20 million dead, the majority of them young men was a sizable percentage of Russias workforce.
Zhukov is widely regarded as one of the best generals of ww2, the above mentioned operation bagration achieved complete strategic surprise on the germans. No mean feat seeing as nearly 2 million Soviet troops took part in the offensive. Earlier in the war poorly equipped and trained infantry were sent against superior forces not because of poor leadership, because there was nothing else to send. Russia suffered staggering losses in both trained men and equipment during the german advance and needed time to build more tanks and planes and train men to use them. It was done out of neccessity rather than a disregard for human life (though there wasnt much of that on the eastern front) and bought the russians enough time to turn the tide in their favour.