Guizhou Sheng Travel Forum

My friends and I will be heading to Guizhou for the May holiday week. Our tentative plans are to depart Shanghai (plane/train) on 29/4 (Sat) and be back in Shanghai by 7/5 (Sun) night, or at the very latest, early morning 8/5 (Mon).

1) What are your best recommendations for sightseeing in Guizhou?
1a) Ideally, we'd like to visit a Miao village, a Buyi village, a Shui village and a Dong village, without any repetition. I don't mind missing out Buyi and Shui villages due to time constraints, especially if they're not very photogenic... any opinions?
1b) We'd also like to see 1 waterfall, 1 group of caves and enjoy 1 rafting experience. I've thought about going for Huangguoshu Waterfall, Zhijin Caves (instead of Longgong Caves) and the rafting at Maling River Gorge... any opinions? I've heard that the Zhijin Caves are not very well-run... If visiting Huangguoshu Waterfall, I'd ideally leave it till the end of the holiday week when there should be less tourists there.
1c) It seems that northern Guizhou isn't very interesting, so I'm skipping that. Any other recommendations for the rest of Guizhou will be welcome!

2) Apart from me, there should be about at least 4 other friends coming along. The number of people coming along could increase by quite a lot, but I'm not keen on having such a big group, due to logistics problems! It's pretty hard to satisfy everyone in a big group, and also less freedom for everyone. If I had my way, I'd take only a maximum of 3 other friends, and that's it. Any ideas on how to manage this? Especially since I don't want to offend anyone by being rude...

3) Should we fly both ways, train both ways, or train and fly once each? I'm getting worried about the budget and time constraints! Train is cheaper, of course, but takes 33 hours each way; flying would be about 1500 RMB each way!

4) Any recommendations on where to hire a vehicle for 5-10 people? Driver recommendations will also be very welcome. Minivans seem to take a maximum of 9 people... :(

5) Any festivals during this period that'll be worth seeing? As far as my research shows, there're a number of festivals on 5/5 (Fri) as it's the 4th day of the 4th lunar month.

6) Any recommendations for where to stay will also be very welcome! :) We're on a student budget, so nothing too expensive.

Thanks in advance to all for any advice offered. Happy travelling!