It's not all the exact dates, but this should help out a bit:
1:
This post places the Woolery episode in June 1976, but it's not clear exactly what day it aired.
2: Vanna's first, according to Brad Francini, was Dec. 13, 1982.
3: The first syndie show...Brad places it at Sep. 12, 1983, but I know the date varied within markets.
4: The first day of the Big Month of Cash...sometime in Sep. 1987, possibly the 7th.
5: The first day at Radio City Music Hall...someone here said the weeks at RCMH aired from Nov. 14-25, 1988, but I forgot whom.
6: First day with the current puzzleboard was Feb. 24, 1997.
7: The 4000th episode aired on Nov. 10, 2003.
8: April Fools Day, 1997
9: Pat's last show, again from Brad, was Jan. 9, 1989.
10: The 10th anniversary show...all I heard was 1992. Not even a month.