I am thinking of the following routing for a DONE 3 for my wife and I next summer, but booking soon.

ICN-HKG-JFK-SFO-DFW-ANC-DFW-YVR-LHR-DXB-LHR-HEL-LHR-SIN-NRT-HKG-ICN

This is 16 sectors, but I was wondering about the return into Asia- can i stop in SIN, and then in each of the other cities, if the outbound ICN-HKG-JFK is only a transit through HKG?

Also, this routing comes out at 48311miles- any thoughts on how to increase that?

Thanks in advance.