Is Kunming, Beijing and Yangtse Cruise possible in a 10 day holiday?

Yes, you can make full use of 10 days to tour around these places. The route can arranged this way:
Day 1-4: Beijing (Forbidden City, Great Wall, Summer Palace, etc. )
Day 5-9: Yangtze River cruise (Yichang - Three Gorges Dam - Chongqing)
Day 10: Kunming (Yunnan Stone Forest)

Personally, you can join a tour to make the journey more efficient. Travel China Guide is recommended. They can provide detailed travel routes for you. If interested, their contact information is traveltravelchinaguide.com.
May help!