25
Yes. A tiebreaker game to determine playoff berth is not considered a playoff game, since it is not a playoff game it counts toward your regular season statistics. Also, playoff games do not count toward either season or career statistics.
No. The most playoff wins needed for a world championship is 11.
Yankees 54-62
The NFL.
The New York Yankees with 47.
1999 cincinnati reds
Prior to the 2010 MLB post season, that was Game 1 of the 2004 ALDS.
Florida/Miami Marlins. They've only made the playoffs twice (1997 & 2003), but they won the MLB championship every time that they did.
Now that Tampa has made the playoffs, every single MLB team has made the playoffs at some point in its history, although Washington hasn't made the playoffs since they moved to DC; their last playoff appearance was in 1981 as the Montreal Expos.
4
Not the team that lost