i disagree on these typings:
montaigne entp
lennon xntp
eco intp
plath infj
hume entp
eleanor infj
i also see werther as an infj, although i see charlotta as an enfp. and albert as an istp. that story makes me sad. werther's descriptions of charlotta's ability to lighten the mood, sparkle, and find other people with such gentleness feel quite enfp to me. his eventual implosion, and his super drippy Fe language, and his Ni re-framings when he talks to albert seem infj all the way. he seems addicted to her Fi and the warmth she brings to everything she touches. plus an enfp male is not reading ossian poems as a way of bringing to light his truest feelings that he cannot express. that's infj.
Hm, interesting.
Concerning your first corrections: what makes you see these six as Thinkers and / or Introverts?
All of them reported themselves / were reported to be social, active, open, enthusiastic, jack-of-all-trades, thus extraverted percievers (i.e. extraverted when feeling healthy and happy, while their introversion only came as they grew suicidal. Genuine introverts aren't suicidal, they happily prefer introversion.)
All of them were known as rather warm and friendly to be with too, making social contact easily, but always with some idealistic, not egotistic goal in mind. Reports of ideal love, close friendships, warm rapports, sensitivity and compassion. In their public life they work for compromises, negotiations, peace, freedom, fairness and cooperation: idealistic NF-goals bringing people together, rather than striving to achieve, conform or command. Their extraversion and immediate trust- and connection-building talents seem not to be competitive (xNTx) nor aloof (INxJ).
Still spells ENFP to me.
Re the young Werther and the other characters in the book:
Charlotta is a well-liked and well-behaved, socially aware young Feeler, but definitely more S than N. Very grounded, this is one of the things that attracts Werther. Her calm and stability soothes him, while he is jumping from idea to idea and suffers from his overactive imagination of either bliss or gloom and the swinging between ups and downs of his mood. She is very conscious about the needs of her family and her fiance and her obligation to fulfill them regardless of her own needs = xSFJ. Guess slightly extraverted.
Albert is the most obvious SJ I read about. I suppose Introverted because he shows little competive take-chargeness relating to Werther. He has no imagination, rebellioness or intuitive visions whatsoever. ISxJ, most likely a sturdy, well meaning, duty fulfilling, traditional ISTJ.
As for Werther himself:
Caveat: I've read the German book in Danish translation and now I'll attempt to translate a few quotes in my homemade English

.
They're from the first part of the book, introducing to us the social butterfly and inner judge of untamed Ne and awakening Fi in the young ENFP:
"May 4: Poor Leonore! And yet I was innocent. Could I help that a passion grew in her poor heart, all the while the coy graces of her sister gave me a pleasant entertainment? Still - am I completely innocent? Didn't I feed into her feelings?"
(Ooh, I have to beat them away with a stick! I dunno why???

)
"May 13: Sure, I know that we are not all equals and neither can we be; but I am all the same of the opinion that those who believe it is necessay to keep the socalled mob at arms length, is just as reproachable as the coward who is hiding from his enemy because he is afraid to be the lesser of the two."
(Egalitarian, makes idiosyncratic rules of interactions)
"May 17. I've made a lot of aquaintances, but company I have yet to find. I do not know what it is about me that attracts other people so much; there are so many that likes me and grows attached to me and it makes me sad when our roads must part after a short while."
(Extraverted, wanting a soulmate)
"August 12. "No matter what you talk about", I said [to Albert], "you keep saying: That is stupid, this is wise, that is good, this is bad! And what do these words mean? You have hardly examined the background for an action. Do you know with certainty the reasons for this or that to happen? If you had made an effort to examine it, it is unlikely you would be so quick in your judgments!"
(Now the ultra-Perciever has about had it with this ultra-Judger.)
= ENFP :hi: