If we had taken Berlin, certainly there would have been casualties, maybe not on the Russian scale, but significant number. Given that Churchill wanted to keep it and the US was essentially leaderless (HST was kept a bit in the dark) I am not sure we would have pulled back.
If Stalin had decided that Berlin was his and fighting broke out, where would it have ended?
The US wanted the Soviets fighting in the Pacific. The US would have pulled back. Churchill may have agreed to pull back, IF Poland was freed (the reason they went to war). But Churchill lost the election and was out of power.If fighting had broken out between the US and the USSR, the Soviets may have had some early successes, but in the long run, they would have been creamed.