It is now obvious how Lam-chan fits into the ending. Also, I was right about Blaze and Klein, Raul’s former classmates that were added for the anime; I didn’t want to say more at the time, but it should be pretty clear now.
They’re definitely tracking the Ecchi manga, despite things being reordered to accomodate the Amada story. They even had Lam flip up Elza’s skirt to show off her sexy panties, although they changed the reason and the audience.
It looks like I was wrong about Shell, though; he’s in it pretty deep.