I think they're both idiots - she just as much as him. I mean, she absolutely HAS to realize at this point that it's him who is moving her bench; she was the one who shut his storm door after all, when he demonstrated that it banged against the bench. If she doesn't realize it, then she's a very dim soul and the LW would be advised to keep that in mind when speaking to her.

I definitely think he needs to man up and just tell her about the situation. He's being whiny, annoying and passive-aggressive with his bizarre little hints. However, the fact that she keeps moving the bench back every day, just 2 INCHES...? That seems very strange to me, and she's displaying the same passive-aggressive behavior as the LW (if she does realize that it's him moving the bench). And why hasn't she said anything to him about it? Maybe she's trying to bait him to come talk to her?