Short answers, pulled from the story.
Bill Russell won eleven NBA championships during his thirteen seasons with the Boston Celtics, from 1956 to 1969. Two of those championships were won while he also served as the team's head coach, during the 1968 and 1969 seasons.
Yes. Russell became the first Black head coach in NBA history on the 16th of April 1966, when he agreed to serve as player-coach of the Boston Celtics following Red Auerbach's retirement. He went on to become the first Black NBA coach to win a championship.
The Bill Russell NBA Finals Most Valuable Player Award is the official name of the NBA Finals MVP trophy, renamed in Russell's honor on the 14th of February 2009, as announced by Commissioner David Stern. Russell received the announcement during halftime of the 2009 NBA All-Star Game.
Russell and Chamberlain were close friends for most of their careers, despite being fierce on-court rivals. Their friendship broke after the 1969 NBA Finals when Russell's comments about Chamberlain's injury were overheard by a reporter. The two did not speak for more than twenty years until Russell personally apologized, after which they were regularly seen together at public events. When Chamberlain died in 1999, his nephew said Russell was the second person he was told to call.
Russell experienced sustained racial abuse throughout his time in Boston. Vandals broke into his house in Reading, Massachusetts, covering walls with racist graffiti and damaging his trophies. He described Boston as a "flea market of racism" and refused to attend the retirement of his jersey in 1972 or his Hall of Fame induction in 1975. A partial reconciliation came in 1999, when the Celtics re-retired his jersey at the FleetCenter before a sellout crowd.
Shortly after Russell died on the 31st of July 2022, the NBA retired his number 6 league-wide, making him the only player in history to receive that distinction. He became the third person in North American major professional sports to have a jersey number retired across an entire league, after Jackie Robinson and Wayne Gretzky.