It seems to me the best thing to do is to differentiate between: a state of being: being male, happy, angry, kind, cruel, a soldier, a nurse, a teacher, etc, and taking some action: doing homework, kicking a ball, taking a class, standing up to teach some children, fighting a war, catching a thief, etc. These are things that people do.

In all honesty "to be" isn't really a necessary verb. There are a lot of languages that get away with not having it. "To be" signifies that something exists basically. a good way to describe it is "this = that" so "I am happy" is "The person that is myself = happy" ... if that makes any kind of sense. "To do" is a weird verb in that it implies basically every action. It's a very general verb. "what do they do" basically is the same as asking "how do they make money" There are also many languages that use "to do" to make verbs that don't exist by themselves in the language. "Faire du foot" in french (lit. To do football [soccer] or in japanese benkyoo suru (lit to do study)" Another good example is that you can replace any verb with to do (with context). So if you ask someone something like "Are you swimming" they can say "Yes I'm doing it" I hope this helps.

I am also teaching English in Jeddah for a few years now, maybe we can share our notes and stuff.

Thanks :)

You might want to give what I wrote here a read: http://www.italki.com/question/263787