about Marianne's opinion on JA herself! You can just imagine her coming up with something very much like Charlotte Bronte's dronings about S&S.

And yes, I have absolutely no doubt that JA was comparing Willoughby's two "departures". After all, the first was merely mysterious. His emotion as he left Barton Cottage nearly matched hers. It could certainly have been seen, and was so seen by the three Dashwood women, as evidence of his continuing attachment to Marianne. Your characterisation of her reaction as "formulaic" is just right, IMHO. Initially, "Marianne came hastily out of the parlour apparently in violent affliction, with her handkerchief at her eyes; and without noticing them ran up stairs". You know that's real. The rest isn't, except in her own mind.

I also like Jeffrey's idea that Elinor is mourning Edward as well as empathising with her sister. He pops up just often enough in the story to keep him "on the boil" in Elinor's (and our) consciousness. She hasn't forgotten him, and we ought not to forget that fact. I'm sure that in her tears in Ch.29 are more than a few for him.