2 weeks in Vietnam, how's my itinerary look?

Hi everyone,

I'm just looking for a bit of feedback on the itinerary I have planned. Anything I should add or remove, general thoughts, etc are all appreciated!

Sept 29 - Arrive in Hanoi, tour Hanoi
Sept 30 - Ha Long bay tour
Oct 1 - Ha Long bay tour and sleeper train to Dong Hoi
Oct 2 - Bus to Phong Nha, chill out, etc
Oct 3 - Cave tour in Phong Nha, back to Dong Hoi for the night
Oct 4 - Train to Da Nang
Oct 5 - Tour Da Nang
Oct 6 - Flight to Dalat
Oct 7 - Canyoning Excursion
Oct 8 - Flight to Saigon
Oct 9 - Saigon
Oct 10 - Flight home

I've timed the flights so they would be in the morning and we would have the day on arrival in each location.

The main things I've found that I really want to do are the cave tour in Phong Nha and the canyoning in Dalat. Is there a better way to make my way to both of these? Is my time better spent elsewhere? The trip could also be reversed to go South to North.