6.) Why did the Japanese conquer the people they colonized?

Because Japan's natural resources are not particularly rich, having a colony would be particularly beneficial to Japan.

Japanese colonial empire. The Empire of Japan in 1942. The Japanese colonial empire constituted the overseas colonies established by Imperial Japan in the Western Pacific and East Asia region from 1895.

Not sure if it’s right but I looked it up hope it helps!

There are two similarities: structure of government and checks and balances, you forgot two add following options but theses two i mentioned are only main similariteis, hope i was and it will match two your options