The time for Vietnam sounds about right. There's a lot to see and moving around can be slow.

3 days in HK should be enough to get the gist of Central and Kowloon. You could also manage to fit in a trip to Lamma Island with a return via Aberdeen or a day in Macau.

Don't stay for a week in Manila though. Either fly to other places (PPS, CEB, MPH/KLO for Boracay) or if you don't want to go anywhere else, 1-2 full days is enough. You could then add more time in Bangkok, which is a huge city.

Unless you consciously skipped Malaysia, consider adding Kota Kinabalu. You could do an MNL-BKI leg very cheaply, and if you wanted even more travel, perhaps a ferry to Brunei via Labuan, and then onwards from BWN to SIN/KUL. Or a short hop to East Sabah (SDK) to see all the wildlife.

Note that you'll be travelling during the typhoon season. It's possible that there will be flight disruptions or, in the Philippines, even some flooding. It'd be best to keep your flights (ticketed separately) spread out in so that any unpredictable weather does not ruin your whole itinerary.