She also connects to people with imaginative, indirect ways, which seems Ne over Fe to me. However, I could see an argument for Ni coming out through Fe.
My point is, I don't think enough points to INFJ over INFP or vice versa. Some things point to one over the other, but a lot of it is neutral. I think if her character spoke more it would be more telling. We mostly just observe her in the movie and have a narrator talking to us.
Well, maybe I would be able to see the ENFJ, but certainly not the INFJ, for the simple reason that Elizabeth strikes me as a total extrovert. She even openly despises Mr Darcy for being so antisocal. Besides, if she was an INFJ, she would have to be the same type as Anne Elliot, and I'm afraid I fail to see any similarities besides both of them being clever. However, to be honest, I don't buy the ENFJ either. If she was an ENFJ, she would have to be Fe dominant, and I really don't think she's that in tune with community or even so concerned about others - the opposite is the truth most of the time, she is very independent and doesn't care much about following norms. She does have a certain 'Fe' personal charm, but that could very well be the Tertiary. (Every ENTP I know is an extremely charming person.) I don't even see her as an NF, to tell the truth - the thing she values the most about herself seems to be her independence and her keen wit, which is typical for ENTP women from what I've observed. Plus, most of her talks with Mr Darcy are heated intellectual discussions; she sees her NF sister Jane as a 'too kind' dreamer; her INTP father relates to her the best; and she's an almost polar opposite of her obnoxious ESFJ mother. All of this leaves me with an NT.
As for your arguments, I'm not sure if I find them valid. firstly, I don't see that much self-discipline in Elizabeth at all, what I see first and foremost is pride and opinionatedness, and she doesn't really direct her intelligence anywhere, apart from enjoying her battles of wit. That doesn't exclude ENTP at all. Secondly, I do think that Elizabeth acts pretty impetuous and passionate from time to time.
Elizabeth dislikes Darcy for not being social - exactly, he is not meeting the social requirements for a polite gentleman and his rudeness offends her. I hardly see an NT being so offended by this, but a Fe-aux, yes. She is also embarrassed by her silly younger sisters and concerned about their reputation, whereas her INTP dad just laughs at them. I don't see an ENTP being so concerned about impropriety. She also uses her intelligence with her father in trying to see why something is a bad idea. I feel there's some Ni in her foresight of how her sister's going off with the troops is not smart.
She seems too quick to judge people and comes to conclusions too quickly (ie. Mr. Darcy and Mr. Wickham's characters were surmised very quickly by her, too quickly) to be Ne-dom. I also find ENTPs much more abrasive and less emotional, and while she has a sharp tongue, she avoids outright rudeness unless she is provoked and gets emotional. Most NFJs I know enjoy verbal wit and intellectual discussion and I don't know any NF woman who does not value independence. Don't mistake Feeling for softness.
She also seeks out a lot of time alone to meditate on her feelings. In the book, she seems to prefer being alone or not among a large group. The movie makes her a lot more vivacious and rebellious in spirit. Although, I could see her as a low E.
I don't see Jane as NF at all (I'd say ISFx), but that's not what we're discussing.