Communists.
On the Jews.
The jews, he believed that they were to blame for Germanys financial crisis after WW1.
Hitler wrote, Mein Kampf. He, and the Nazis, blamed the Jews for German's problems.
Japan, too.
Yes. The Nazis tried to dress up Kristallnacht as a popular response to a Jewish act of terrorism, but it was in fact only Nazis and their agents who produced the violence and destruction.
A blame game is a situation in which people attempt to blame others rather than attempting to solve a problem.
No need. You should be working on fixing the problem instead of fixing the blame.
Gypsies, mentally/physically disabled, homosexuals, all foreigners non aryan descent were blamed and killed in concentration camps and in other manners alongside the jews. They were all deemed a strain on society and were extinguished.
Because they ran most of the banks.
They used defamatory propaganda, blamed the Jews for anything damaging to Germany and generally shamed and humiliated them. There also was a long history of anti-Semitism in Europe, so the Nazis had a strong foundation to build upon. Nazis did not invent anti-Semitism. There was also a lot of pseudoscience around about brain sizes and head measurements, suggesting that some people were just naturally, genetically better than others. Because we as people often want to feel like we are the best, and on the other side, we want to blame something besides ourselves for our problems, the Nazi idea of saying "We are great... they are to blame for all the failure" was a tempting lie.
It wasn't after WW2, but WW1 that Hitler blamed the population you listed. A dictator needs to have groups that he makes into enemies so he can blame conditions on them.
German students are much, much less inclined than popular history in the U.S. to place the blame on the Treaty of Versailles - and more inclined to blame the Nazis.