Anouther factor about the B-29 was the politics that would have gone on over who would control the missions it was sent on. In the Pacific the joint chiefs of staff and General Arnold had to create a new airforce group, the 20th Air Force to operate the B-29. Many generals and admirals did not understand strategic bombing and would have used the B-29 in a tactical role. There was some hard feelings in RAF bomber command and the 8th Air Force (US) over the use of heavy bombers in tactical missions leading up to D-Day and the period afterward. These missions were forced on them by their "superiors". In the Pacific some naval people would have liked to use the B-29 as a long range recon. aircraft.
Anouther potential problem that happened in the Pacific was a B-29 had problems of some type and landed in Russia. Stalin had it copied and produced. The same could have happened in Europe if a B-29 had been forced down in German occupied land. In the Pacific they would more likly to crash in the ocean and not be avaiable for recovery to Japan.
I know it would have taken some time for the Germans to copy and produce a B-29, but they did some pretty amazing things toward the end of the war with their large labor force and they needed a large bomber for their airforce, since the He-177 was a flop.
