some concerns if/when moving to Japan

Greetings, I am seriously thinking of moving to Japan, but I have some concerns. Besides the language barrier, different culture, getting visa etc, I was wondering if anyone has an opinion for few things like bugs and earthquakes. I have read, that in Japan there are some specific bugs like big spiders, mukade, roaches, and the noisy ones, that activate in the summer. I know, that in the north part of Japan there are less of them but, still I was wondering is this like a big problem, or it is a minor thing? Also how frequent are the earthquakes there?