Help me discuss about my Hanoi trip (considering layovers to visit multiple countries)

Hello, friends! I am planning to have a solo trip to Vietnam this November. Here’s my planned trip details:
Manila - Hanoi (layover in Singapore for 14 hrs via Vietjet air)
Hanoi (3 days)
Hanoi - Manila (layover in Guangzhou, China via China Southern Air)

My only out of the country trip is Taiwan from 2 years ago.

I admit that I will not take your advices as a conclusion but at least a precautionary measure. I would like to know if this type of itinerary is a little red flag in the immigration or this is fine so long as I have complete papers with me?

and by the way, I am planning to book through the Agoda app so that hotels are also covered in a one time go.

Any thoughts please? Thank you! :)