Italy surrendered to the Allies in September 1943 and formally ended the war as a member of the winning side.

By early 1943 it was clear that Italy was losing the war. Allied troops had taken Sicily and an invasion of the Italian mainland was imminent. Meanwhile, domestic resentment against the Fascist government was rising: in March 1943, Fiat workers in Turin went on strike, the first large scale labor action since before the war. Allied bombers had reached the industrial heartland of northern Italy in late 1942 and the bombing campaign intensified over the course of 1943. Finally, in July 1943 Mussolini was removed from power and arrested by order of the King.

The new government almost immediately reached out to the Allies to begin negotiating a separate peace. In late August an Italian delegation traveled to Sicily and the armistice was signed on September 3, 1943. The armistice was in effect a total surrender, and as part of the terms the Italian military was required to cooperate with the Allied war efforts in Italy.

Unfortunately, the Italian response to the armistice was rather poorly organized and when it was announced publicly on September 8th, most Italian army units were caught unaware and had no orders for how to react. In addition, the Germans had seen this coming and had put in place plans for just this possibility. In the end, the king and government were forced to flee to southern Italy (where Allied troops had landed in the meantime), Mussolini was freed by the German army and installed in a puppet government in the North. The Italian army was divided, with many units in German-controlled areas which continued fighting against the allies, while others switched sides. Mussolini's northern government lasted until April 1945, when the "liberation" was declared by Italian partisans, and we all know how that turned out.

Thus, at the end of the war, Italy was a member of the allies whose "occupied territory" was "liberated", much like France, and not a defeated enemy to be occupied, like Germany.

In a very practical sense, because there weren't already Soviet troops in Italy at the end of the war.

As to the second, Germany was the most important area in Europe in regard to any potential Cold War hostilities. For that reason there were extensive NATO and Warsaw Pact forces stationed there and lots of military bases. You want your troops, c&c, supplies, etc. closest to the front if fighting is likely.