RE #3: No, a community college is not simply a night school. Community colleges may have classes in the evenings and on the weekends, but, nowadays, when the number of "non-traditional" students has increased dramatically, four-year colleges, universities, and even grad schools (at least the one I attended) do so as well.
Community colleges seem to have differing functions depending on the state/community they are located in.
In my state, they offered college/university-level instruction that typically amounted to roughly the first two years of a four-year college/university degree. Upon completion of the requirements for these first two years, an "associate" degree could be granted. After that, the person could apply to a four-year institution and have the classes that they completed applied to the requirements of the next institution (which may or may not grant full credit for the classes, depending on how the level/content of instruction at the community college is evaluated).
However, community colleges in my state also provided vocational training and certification in various professions that don't necessarily require a college/university degree -- both tracks include some programs that include associated work experience while studying and others that are apart from the work world.