Q1:
MONICA: I mean, why should I let them meet him? I mean, I bring a guy home, and within five minutes they're all over him. I mean, they're like- coyotes, picking off the weak members of the herd.

PAULA: Listen. As someone who's seen more than her fair share of bad beef, I'll tell you: that is not such a terrible thing. I mean, they're your friends, they're just looking out after you.

Q2:
RACHEL: And everybody knows this?

JOEY: Yeah. Cushions the blow.

Q3:
PHOEBE: - and there's five hundred extra dollars in my account.

CHANDLER: Oh, Satan's minions at work again...

Q4:
His method was subject to false positive.