I'm not having Lacerda do the final scoring. He's already a VERY tough opponent that takes a ton of points really quickly. If he does traditional scoring then I don't think he's beatable by anything but the very best players with excellent luck on the weather.
I think you should score Lacerda, he just doesn’t get the extra turn after the fair. Why would he accumulate cash if not to score it at the end? Of course since he has no wine or property, he gets no wine points and a straight 10 points per multiplier tile, which will help compensate for his high cash score. Yes he is tough, but I did ok against him my first time through,and ended up with more VP than he did. Just make sure you beat him in the export area, and do better than 10 points for each of your multiplier tiles.