I thought the b-plot was barely there for the first half, but then was the focus for the second. That was odd. Still, it did nothing for me, and like Big Bad said, seemed like a waste of Alyson Hannigan (and even Kristen Wiig).
I like Moe so I enjoy the episodes based around him - and enjoyed the nod to other Moe's Bar makeovers. Did we always know Chalmers' first name was Gary?
Ben wasn't dead when the island healed him. Plus it was sorta put that Faraday caused his own memory problems by experimenting on himself. And he couldn't remember things day to day, a problem Ben has never had.