Can I apply for the 144 hours Visa free?

I will travel from Seattle - Shanghai (stay 143 Hours there) - Return to Seattle.
That is less than 144 hours in shanghai, can I apply for that visa?
If not, I decided to do this:
Seattle- Shanghai (stay 2 days) - Hong Kong (stay 2 days)- then I will have to go back to Shanghai to take my flight back to Seattle... IS that possible?
Or do I have to do Seattle- Shanghai-Hong Kong- Seattle? and not a trip to shanghai between Hong Kond and Seattle?

I already have the airplane tickets Seattle- hanghai-Seattle. But I can buy the tickets to Hong Kong..
I would need to know so maybe I can cancel my tickets from Shangai to Seattle and just come back to Seattle from Hong Kong?