Tiger, the altitude will have no serious long-term negative effects for the very great majority of people, we're simply not that high, and expanded lung capacity is generally seen as a healthy thing - the physiological limit for acclimatization (beyond which the human body simply cannot modify itself to handle the altitude) is over 5000 meters (although it can still get along for a few months - naturally this requires gradual acclimatization up to this point, and most people probably couldn't do it for even a few months) - but, at 1000 meters, we do not have anything like 1/5 of the problem, as a difference in, say, 100 meters at around 1000 meters is nothing to that of the difference at, say, 2000 or 3000. Personally I feel better here than at sea level, became acclimated long ago to Kunming's altitude (certainly wasn't difficult, I can't even remember it ever being a problem). Note that I've been here 14 years and am in my early 70s, and I grew up at about 300 meters' altitude. Do you know anybody who has developed any real health problems from the altitude here? I don't, though I guess some people with particular lung problems might have.

You're right about air pollution of Chinese cities generally, but there are plenty of cities around the world with worse air pollution than Kunming. Yes, it's worse than it was just a very few years ago, before the cars and rage for construction.
I find it really odd, and a bit amusing, that any foreigners with experience here might feel that daily life in Kunming is somehow dangerous.

I like Salvador's.
Sal's, Wicker Basket and Brooklyn Pizza sell good beans, too. Wicker Basket has the cheapest, but it is a bit boring to sit in. Brooklyn roasts their own.

We will meet again on Wednesday, June 13 at 6:30 at The Park to discuss Nicola Di Cosmo's work, ANCIENT CHINA And ITS ENEMIES: The Rise of Nomadic Power in East Asian History.

I wouldn't take a tour, just go.

What is a 'rice paddy trip'?
Suggest you either leave out either Yunnan or Guilin/Yangshuo - too much running around.