The first two, I cannot give you an answer to(but I am pretty sure they are untrue as Germany itself was reeling back from WWII and also the lack of availability of tissues, I would assume they ate boiled barks off certain trees.

As for the last one, Many Pro-Japanese and Japanese Collaborators were let go by Rhee Seungman. The Americans definitely played a role in protecting them post WWII as many of them were already part of most government positions, and were for the most part Anti-North/Communists. U.S most likely saw that killing off majority of the government work force (not to mention armed force) through purge would only weaken South Korea should there be war with North Korea, there fore most were let go or essentially forgiven by the Rhee administration (although later many cases were brought back up and prosecuted). I wouldn't say that Pro-Japanese people stayed in power since the whole administration was changed however but simply that many went unprosecuted and unpunished.