No, not necessarily. Three weeks is ideal but they can be separated at two in some circumstances. I took a male from a friend at 15 days because he was large enough and she was worried he'd breed his sister or mother. He's totally fine, years later. We are not the Craigslist Guinea Pig Police, much as we may like to pretend we are.
Not sure what you're talking about, I've commented on all of ONE other thread you started, when you were asking whether or not your proposed cage setup would be acceptable for a flemish giant; in this case I was actually wondering if this person had other posts on Craigslist that you'd seen, which made you think he was a breeder, because breeders usually have more than two pigs and usually seem at least moderately more knowledgeable about pigs than this person does. In case you aren't aware, this is a forum and folks are free to comment when you start a thread about breeders or rabbits or anything else; the implication when you make comments like, 'why do you hate me' is that you feel you are waaaay more important than is realistically warranted - I don't care, personally, one way or another about you and since the only comment I've made to you one way or another wasn't on another forum, but rather another thread you started here, I think you're referring to that. In any case, I really am curious to know why you think this person is a breeder; as it is, I don't see anything that suggests s/he is, but instead just a misguided owner with pigs that would likely be better off in other homes, which is why flagging the ad might not be the best resolution in this instance.
Flagging creates a kind of burden for actual breeders who are using CL as a free advertisement. Breeding/selling is against CL rules and so this section of the forum was setup to help prevent them from using it that way as folks who are members here peruse and see ads; but when we're flagging ads that aren't breeders, just stupid owners, that's more of a disservice to the animal and isn't actually discouraging a breeder at all.
I agree and I'm not sure it does much good at all, in all actuality. True breeders just repost and aren't really deterred by being flagged; if they are, they just find another site to sell their animals like Ebay Classifieds or Hoobly. Short of making those doing the flagging feel good about it, I don't see that it serves a real purpose at all. In a lot of cases it seems people are more or less flagging ads they don't like, which like I said, can be a disservice to the pets being rehomed and little more than an annoyance to the folks being flagged.
