What are North Korea planning?

North Korea have submitted plans of their ballistic missile launch to UN aviation and maritime agencies, Closing Velocity have some worrying analysis:

"Connecting the dots between the launch site (orange triangle) and the two danger zones where the two stages will splash (red triangles), we can see where the missle could head --- again, according to the North Koreans themselves:

* They indeed plan to overfly Japan, shedding the first booster in the Sea of Japan.
* Depending on the range of the missile, the trajectory is making a bee-line for Hawaii.

...

Could it actually reach Hawaii? Who knows ... but the North Koreans did recently test an ICBM engine that would put California in reach. Whether that engine will power this missile is unknown."

Isn't life fun!