DL remains a r/t system. Sure he can fly one-way but pay a r/t price if he wants to use DL miles.

I believe DL's Chinese partners also charge YQ which is about as bad as BA's.

OP would have a hard time to get from WUH to PPT. Better to separate the WUH to some gateway, and then from that gateway to PPT. Said gateway may not need to be in US, fwiw.

As for the CC game, he only gets some of it. Way more to learn on both how to accumulate miles and what miles / points to accumulate for the "goals". DL actually is not necessarily the one to focus on.