Documentation for L visa when applying in a third country

I will be visiting Southeast Asia and my intention is to apply for a L type in some neighbor country embassy as I don't know my exact itinerary yet. My concern is regarding the proof of legal stay. "4. Proof of legal stay or residence status (applicable to those not applying in their country of citizenship)"

If I'm only as a tourist and I don't require one for that country that I'm applying from, do I still need to show this? If so, a copy of the hotel booking would be enough? Also, if I'm planning to exit China via Hong Kong do I still need to show a round trip air ticket at the time of the application or only with an onward ticket and a hotel reservation it's enough? Thanks!