Chang is pretty dialed in, good sources, good thinker.
The Koreas will never unite.
NK is so poor, they have minimal electricity and that is something they want from SK badly.
The Kims know that NK has a great hunger for technology, CDs, DVDs, thumb drives, cell phones, etc. The Kims know they will lose control of NK if they don’t modernize their economy.
NK is already working all they can get out of China. They are looking to greatly expand rail access to Russia.
the Kims will never give up their nukes.
They will sign a peace treaty with SK in order to demand US withdrawal from SK. Remember that SK was the only party that refused to sign the armistice in 1953. NK and the US signed off on a truce only.
SK is still technically in a declared state of war with NK. In fact, to keep NK from mapping SK, SK is the only country in the world that doesn’t allow Google mapping.
However, the imagery is so sharp that you can ID automobile types -- so, anyone with Google Earth (and tons of slave labor) could create their own roads layer.
Of course, Pyongyang has lots of beautiful multilane roads -- with little or no vehicles on them. I just checked over three miles of pristine eight-lane roadway in downtown Pyongyang that had a total of one (1) vehicle on it!