OK, refusing to look at previous answers till I post mine:
S
P
O
I
L
E
R
S
P
A
C
E
Quotes first:
Quote 1: Don't know.
Quote 2: Sounds like a CarolM fic? But not sure which one.
Quote 3: Don't know.
Quote 4: It's by Nan Smith - "Middle School"?
Quote 5: "If At First You Don't Succeed" by ML Thompson.
Quote 6: I should know this but I don't.
Quote 7: Don't know.
Quote 8: "Tempus: Four Play" by Female Hawk.
Quote 9: Don't know.
Quote 10: Don't know.
EXCERPT GUESSES:
Now for the excerpts: (Only the ones I didn't get already.)
Excerpt 1: Darn it! Still don't know!
Excerpt 2: A CarolM fic? "On The Other Hand"?
Excerpt 3: Still don't know.
Excerpt 6: Ooh, it's Bobbart with "The Return of Ultra Woman"!
Excerpt 7: Aargh. Still don't know.
Excerpt 9: "A Triangle With Three Sides" by anonpip?
Excerpt 10: Don't know.
OK, now I can go and read other people's answers and slap myself upside the head!