Shelby, thanks for your great post. I agree with most everything you said.
I also want to add that regarding Chantal's "overemoting" and Emily's lack thereof, I expect that the editors' plan was to overexaggerate both women's natural tendencies to play up their opposite natures, knowing they were the final 2. And additionally, I think that the circumstances themselves contributed, in that Chantal's insecurities about Brad (she must have sensed, as all the women did, that Emily was his favorite, all along), and his inability to really assure her of his feelings (since she wasn't the one he was falling for), caused her to be more prone to meltdowns, whereas Emily, it appears, never really was confronted with Brad showing more interest in anyone else, so it was much easier for her to remain calm and in control of her emotions. Brad now tells us how upset she is watching the show and it may be because she is now becoming aware of how far things progressed physically with the other women, something she probably didn't think about then since he was so clearly pursuing her and her alone, and was such a perfect gentleman and moved so slowly with her besides. She may be seeing a different side of Brad and it is freaking her out.