On the roads skirting Genoa this fall, I was impressed with how large it was, but that's not a selling point. Rick only covers his top 50-or-so cities in Italy for an American tourist. He wants you to get the most bang for your buck and your limited travel time and therefore recommends smaller Riviera towns. But if you've experienced much of what's in the book, you'll need more and should branch out.
The opportunity to visit relatives and have a real, local experience with them is something else entirely, which could turn into a connection you want to keep. Two weeks in Lavagna is a long time and a direct train from there back to Genova only takes slightly over one hour each way.