Could have, but the lines were already drawn. We had to hand some territory over to the USSR after we occupied it. I think that the Red Army suffered about 1 million casualties in the entire Berlin-area operations. Better them than us, especially since we were going to give it to them anyway. Patton wanted to re-arm the German army and attact the Russians. Interesting idea, but not politically do-able. The US Army was just getting totally up to speed in 1945, and the Red Army was starting to finally run low on manpower, and was using Allied-supplied equipment in huge quantities, which would have ended immediately, so, plus Allied air power, it might have been posssible to drive the USSR out of europe. However, the US was planning on an invasion of Japan, and all the military force was needed there, so it wasn't considered.
The lines were drawn. Handing over that land would have sucked, and Ike and Bradley were correct about that. A side note, Napoleon's 1st exile was caused by the Battle of the Nations at Leipzig. When I toured it, I learned that many of the last Americans to die in Europe in WWII died at that monument (it is a great monument and sad that Americans died and then gave the land back).
Yes, but the West also got territory in northern Germany back from the Soviets after they occupied it. And let's not forget - despite not taking Berlin with their troops, the West got a substantial portion of it in the form of West Berlin after the war.