Thank you for sharing this lovely report. You both clearly had a great sense of adventure and the right spirit to take it all in stride.
200,000 dong for some rice and a few pieces of chicken was definitely rip-off. :) That's the price at a fancy restaurant in Saigon, not at a northern village.
And the majority of Ho Chi Minh City residents call their city Saigon. Some northerners prefer to call the city HCM City. You probably know why. As a Vietnamese-American, I don't even dare to call the city Ho Chi Minh City in any overseas Vietnamese community.
Highway 4C is so beautiful from your report. Definitely on my list now.