One month southeast Asia itinerary - critiques?

I`m heading to SEA late November for one month, concentrating mostly on Thailand, but also hoping to do side trips into Myanmar, Laos, and Cambodia. I`ve outlined my planned route so far, but if anyone has some helpful suggestions or warnings, I`d appreciate it.
If it looks too rushed, I know, it is. Typically I`m the kind of traveler who likes to settle in and get to know a place and not move around too often, but this is my first trip to SEA and is sort of an orientation tour for later trips. It`s also half business, half pleasure, since I`m a photographer and the purpose of this trip is to build my stock portfolio.
I`ve checked to make sure the flight connections work.
With that, here`s the plan:
11/21 - Arrive BKK 11:25pm. Sleep at the airport during 8 hour wait. 11/22 - AM, fly to Phnom Phen. Rest. Visit Tuol Sleng and the Killing Fields. 11/23 - AM, take the fast boat up the Tonle Sap to Siem Reap. 11/24 & 25 - Angkor Wat 11/26 - AM, fly to Chiang Mai, rest. 11/27 - AM, at leisure. Take 15:45 flight to Mandalay, Myanmar in transit to Inle Lake. 11/27 - 11/30 Inle Lake 11/30 - Take 13:15 flight from Mandalay to Chiang Mai. 11/30 - 12/6 Northern Thailand at leisure - Chiang Mai, Mae Hong Son, Pai, trekking. 12/7 - Transit to Chiang Khong, on the border with Laos. 12/8 - Boat from Huay Xai to Pak Beng. 12/9 - Boat from Pak Beng to Luang Prabang. 12/9 - 12/11 Luang Prabang 12/12 - Fly from Luang Prabang to Krabi via Chiang Mai 12/13 - 12/17 Krabi area (Raileh Beach, Ao Nang, Phi Phi) - diving, sea canoe, rock climbing, lounging on the beach. 12/17 - PM, Bus to Surat Thani and take the overnight train to BKK. 12/18 - 12/20 - Bangkok. 12/21 - Fly home.

I just came back from Cambodia. without driver). Depending on when you arrive it could be a bit tight to visit both. Why not have a look at the Royal Palace? KF are depressing but not much to see. Tuol Sleng would be enough if you want to get an ipression of the horrible past. 4 pm the same for the next day. You have access to the temples with that ticket from 4pm onwards and could catch some impressions. which means you will pay 40 USD and get only 2 days out of it. If you want to see all the important temples 3 days are necessary, otherwise if you ok with just seeing the really big attractions then 1 day (+ the afternoon before) could be enough.

the first day, but came back every day to Angkor and the one up the mountain until sunset and to wander about the place, one day pass don?t gives you a chance to relax.