"what if they are too stupid to get the irony and still believe that he is really a khazakstani or that the point is still about what geeks khazakstani's are (and what a joke their soldiers are, how easy it is to kick their heads in etc)."

Yeah, that's always the problem, isn't it? It can't be helped. There will always be such people, unfortunately. It's part of life.

I can understand that people are angry he used them and didn't let them in on the joke...but looking at it from his point of view that would definitely work the best for creating genuinely funny satire in an improv way and making it convincing, rather than having people just act it out as a script.

Practical jokes only work if the people you play them on are fooled, but the people who get fooled aren't necessarily going to like it when they find out. In America, if people don't like something, they tend to sue. That's one of the real problems with modern America. It wastes a hell of a lot of time, money, and effort...but it sure as hell keeps the lawyers employed, so it's not all bad, right? ;-)