It's fun to be an amateur economist. I would quibble about your first point, because when you get right down to it, most economic activity is part of an ongoing bubble. There is a base level of goods and services that is needed for people to survive; that's the subsistence level economy. Everything beyond that is based on people's wants and desires, hope for comfort, and attempts at gaining security. And the way you do it is by taking risk and getting a profit from that risk. As long as everybody agrees that the dollar, for example, is the right currency to hold, then it's the right currency to hold. Or that big houses are valuable, or that long August holidays are the right way to spend time.

That's why it's hard to get out of a big depression: You have to build up people's confidence so that they will take out loans to buy stuff so that others will have work to do.