Do oscar winners automatically become members of the Academy?

Answer 1

Yes and no... You can be considered for membership once you're nominated but it does not mean that you automatically become a member. Check out the following excerpt from the Academy's website: -

"Membership in the Academy is by invitation of the Board of Governors and is limited to those who have distinguished themselves in the arts and sciences of motion pictures. The criteria for admittance include: a body of work in motion pictures that reflects the high standards of the Academy, an achievement of unique distinction, or the making of an outstanding contribution to the film arts or sciences.

Members represent 15 general areas – actors, animators and short film makers, art directors and costume designers, cinematographers, composers and songwriters, documentary filmmakers, directors, executives, film editors, makeup artists and hairstylists, producers, public relations specialists, sound technicians, visual effects experts and writers.

A candidate for membership in the Academy is normally sponsored by at least two members of the branch for which the person may qualify. Each proposed member must first receive the favorable endorsement of the appropriate branch executive committee before his or her name is submitted to the Board of Governors for its approval. Individuals nominated for Academy Awards who are not already members of the Academy are considered for membership without the need for sponsors."

Answer 2

Good question....

Sorry I do not have the answer check the oscars website I bet you can find something

Answer 3

No, I don't think so, although the audience does have a vote.