Carl could potentially be an interesting character if he were played by a different (preferably slightly older) actor. Personally, I'd find the show more interesting if Lori and Carl were both killed off. It would certainly spin off Rick in a much
more volatile direction. Callies' interpretation of what the scripts hold is often different that what I see on screen, so who knows how the scripting really comes across? Let Glenn and Maggie procreate if they need babies.
If the writers are under the impression that there's rooting value in Rick and Lori "getting together" again and becoming a stable couple, they're egregiously mistaken. IMO, the Lori character is beyond redemption. If they wanted a full on sexual/romantic story, they'd be better off killing off Lori and paring Rick with Andrea when she comes back. Don't laugh--with some more character development on both sides, the pairing makes sense. I understand they're inching towards that in the comics. Some folks are saying, "No no, she was in love with Shane." Andrea was not in love with Shane. She was on a high from having killed those zombies on her and Shane's day trip and she felt like taking some pleasure and fucking an alpha male. He was the nearest available.