What is the result to demand if we see an increase in supply?

There is no effect, supply does not directly affect demand, the only effect is on the quantity demanded, which would decrease.

What are some typical careers in the finance industry?

Investment banking, corporate finance, private equity.

If assets increase and liabilities decrease by an equal amount, what is the corresponding result of equity?

Equity would not be affected due to the fact that Assets equal liabilities plus equity, so the assets and liabilities equal each other out and equity remains unchanged.