Long story short you will want to be going back and forth between /nin and /dnc. Use /dnc when you are using the blm frame as well as the melee frames, to keep them skilled, as well as depending on the situation. And then use /nin when using whm and full storm walker frame. So 40+ do your own thing, find your playstyle.
This word has been overused, but remember VERSATILITY. PUP's greatest strength is being able to control any situation, and adapt to it. Which means you'll have to act accordingly.
Ps never let your skills gimp.