Forgive me in advance if these were already answered.
1) Can someone please the real life reasons
Richard Masur (David)
Mary Louise Wilson (Ginny)
Glenn Scarpelli (Alex)
& Ron Rifkin (Nick)
left the show

2) If there was any mention on the show why Ginny & Alex's characters dissappeared
We knew David left for California and Nick died

3) With all the Youtube clips floating around, there's no montage of "Things that Schneider says"

4) Did David & Bob (Barbara's admirer) show up to Barbara's wedding?

5) Is there a listing of episodes in which certain characters appear (Cliff, Bob, Beerbelly, Mrs. Larue, etc)

6) Why didn't Mr. Conners & Mr. Davenport appear in any episodes together?

7) In the opening credits of season 6, the length of time it takes to show the 4 main characters (Ann, Schneider, Nick & Barbara) is the same length of time it takes to show Ann, Schneider, Nick, Alex & Barbara; it looks like they don't speed up the fancy 1981 graphics at all to accommodate Glenn Scarpelli and they both end around the same time when Schneider puts his head on Ann's shoulder

8) If everyone knew Season 9 was the final season, they should've brought back some of the old characters to spice up storylines, (e.g. Ginny becomes a junkie)

Forgive me in advance if these were already answered.
1) Can someone please the real life reasons
Richard Masur (David)
Mary Louise Wilson (Ginny)
Glenn Scarpelli (Alex)
& Ron Rifkin (Nick)
left the show

2) If there was any mention on the show why Ginny & Alex's characters dissappeared
We knew David left for California and Nick died

3) With all the Youtube clips floating around, there's no montage of "Things that Schneider says"

4) Did David & Bob (Barbara's admirer) show up to Barbara's wedding?

5) Is there a listing of episodes in which certain characters appear (Cliff, Bob, Beerbelly, Mrs. Larue, etc)

6) Why didn't Mr. Conners & Mr. Davenport appear in any episodes together?

7) In the opening credits of season 6, the length of time it takes to show the 4 main characters (Ann, Schneider, Nick & Barbara) is the same length of time it takes to show Ann, Schneider, Nick, Alex & Barbara; it looks like they don't speed up the fancy 1981 graphics at all to accommodate Glenn Scarpelli and they both end around the same time when Schneider puts his head on Ann's shoulder

8) If everyone knew Season 9 was the final season, they should've brought back some of the old characters to spice up storylines, (e.g. Ginny becomes a junkie)

Sorry that I can't answer your questions, but I just want to say that Ginny as a junkie made me laugh. You mean she wasn't originally?:lol:

Richard Masur was written out of the show because Bonnie Franklin pushed for the show to be about a divorced woman trying to be independent without a man

Mary Louise Wilson was written out because Bonnie Franklin was threatened by her. She felt being upstaged

Ron Rifkin I was glad he was off the show.

Ginny the Junkie made me laugh. And it also would have been the first interesting thing about that character. I think producers were hoping Ginny would be ODAAT's version of Willona of Good Times, but this character never seemed to fit in. MLW may be a great actress in other projects, but she wasn't given much to work with here. I read that she asked Norman Lear to be let out of her contract and, considering Ginny's lack of relevance to the show, I find the idea of her asking to be released to do something else more credible than the rumor that BF went all Linda Lavin-ish on her and got her fired.

I, too, would have liked to see an episode with both Connors AND Davenport. The 2 characters seem so different, I think it would have been fun to see them actually interact.

Regarding Alex, I recall that in the first episode of Season 9, Ann mentions that Alex has left to try living with his mother again for a semester. She expressed some concern about whether it was a good idea, and then new husband Sam just completely dismisses her concern, clearly happy that the kid is gone and they will have the apartment all to themselves. I don't believe Alex was ever mentioned again after that first episode.

I remember hearing an interview where Glenn said it was thought that Season 8 would be the last one, so he started looking for his next job. By the time Bonnie decided she wanted to go ahead and do a 9th year, he'd already gotten the job on NBC's Jennifer Slept Here.

Also...how come there wasn't an episode with Schneider's wife (of one week)

He would behind the show like the director and stuff.