Air quotes are typically double quotes, or possibly angle quotes (guillemets) according to wikipedia. It is not clear who invented air quotes, and how they relate to sign languages.

According to Alan Greenspan, there could be

a flaw in the model that I perceived is the critical functioning structure that defines how the world works.

Would this be self-interest, which guarantees the best possible outcome?

The sentence What you are will show in what you do appears in "The Education of the Wage-earners" by Thomas Davidson (1840-1900). This is a quote commonly attributed to Thomas Alva Edison (1847-1931).
The Development of Thomas Davidson's Religious and Social Thought