What are the connotations of "va'Yevarech Osam"?
Ramban: Adam and Chavah were created, not born to parents. Consequently, their ability to have many children (which are currently under discussion) was not a natural phenomenon, but the result a Berachah that followed their creation.
Seeing as 'Adam' is a general term that pertains to all of mankind, why did Hashem call Adam and Chavah by that name?
Ramban: Because they were the blueprint from whom all of mankind descended.
Yevamos 63a: The Torah writes "Va'Yikra es Shemam 'Adam,'" following "Zachar u'Nekevah Bera'am," to teach us that a man without a wife is not called 'Adam'.
See 5:2:2:2. Why is a man withot a wife not called 'Adam'?
Maharal #1 (Tif'eres Yisrael Ch. 36, p. 105): Though marriage, a woman enters the domain of a man and completes him; together they are called an "Adam."
Maharal #2 (Chidushei Agados Vol. 2, p. 31, to Sotah 4b): The male is the Tzurah to the female, together they form one unit. 1
The Gemara in context is explaining the severity of adultery. Maharal explains that it is tantamount to encroachment upon the very existence of another. Two entities cannot occupy the same existence, and the inevitable result is the destruction of the encroacher. See also Maharal (Chidushei Agados Vol. 1, p. 136, to Yevamos 63a) - Tzurah cannot exist by itself; any Tzurah needs a Chomer in which it is actualized.
Why does the Torah discuss creation of man in the singular and in the plural?
Peninim mi'Shulchan ha'G'ra: Hashem's intent was to create two, so woman would be a helper for man. In actuality He initially created them as one, so there would be love between them.
