Applicable for the 144 hours visa? What papers do i really need?

I have a German passport, and here is my travel plan:
Norway - Shanghai, stay there for 3 days,
Shanghai - Thailand, stay there for 14 days
Thailand - Shanghai, for 2 days
Shanghai - Norway
That would need two visa free transits, right?
I do not need a visa for Thailand, so my passport would be sufficient? And for the onward ticket, is the booking sufficient, or do i need a physical ticket? e-ticket?

Thanks for your help and kind regards