Strawman Has a Point: Only at one point does anyone (Brian) point out that Peter's stroke was his own fault for eating 30 hamburgers in one sitting, and he ends up helping Peter sue McBurgertown anyway.
2.) "Zach" strongly resembles Stewie in looks, mannerisms and voice.
3.) Being in a relationship with someone like "Zach" would almost certainly get her sent to prison (or, at the very least, have her branded as a sex offender for the rest of her life).
However, if Connie did know any of the above, the subplot wouldn't be all that funny. On top of that, Connie doesn't care about Meg or her family (especially since she hates Meg and isn't even aware that Peter finds her attractive) and in shows like Family Guy, the Idiot Ball is always in play, no matter what continuity has been previously established.