It was different ... a clash of cultures. The West's reaction would have been different, but the West DID experience fighting against the Japanese that was as horrific as the Eastern Front and on many locations on the Western Front as well.
Yes but those Japanese forces were typically cutoff and isolated on small islands. Furthermore, the Japanese really didn't have a strategic defensive philosophy since such was viewed as defeatist.
The Red Army was vastly superior to the Japanese. Look at how the Red Army rolled right over Japanese defenses in August 1945.
In the air, the Western Allies would have quickly established supremacy. However, on the ground, it would have been a slugfest. For sure, by May 1945, the Russians had been bled badly. How deep their reserves were, I can't say. Without Lend Lease, they would eventually have been pushed back but the cost would have been very high. We like to think how superior the American soldier was but when reading first hand accounts by Germans, the Russian soldier is always ranked highest.