Katie considers the alternatives that will be lost if she decides to spend her savings on buying a car. what is the economic term for her thought process?

The economic term that is associated with considering the alternatives that will be lost in a situation like this is "opportunity cost," since you're losing the opportunity to do something else.

You could solve them by trying something new that everyone can agree on or make a decision too.

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.