] One thing I've always found rather strange is that Marianne never mentions Colonel Brandon in her list of aquantices she's treated with contempt. Do you suppose its because she's too embarrassed to mention it (and has figured out that Elinor and Mother are hoping she'll marry him)? Or because she never actually said anything to his face?

It does seem odd that she would leave him, of all people, out of her list of people she has treated badly. However, as you say, I think it must be because she has never directly treated him in any manner. All of the insults against him were behind his back and many of them (although not all) were at Willoughby's instigation.

Also, I think perhaps that she has no idea that he has any particular feeling for her at this point. Even though she thanked him and was grateful to him for bringing her mother, and also felt some compassion and pity for his ill-fated history with Eliza, Marianne might still be of the opinion that he is beyond having any deep feelings of that sort and wouldn't imagine him to be so affected by her.