Why does it say, "his soul stuck to Dinah Bas Yaakov? It already said that she is Yaakov's daughter!
Seforno: Because Shechem's attraction to her stemmed from the fact that she was the daughter of Yaakov, 1 who was highly respected by the people of that time. 2
Moshav Zekenim: After he had Bi'ah with her, he did not desire her so much. Primarily, he wanted to cling to Bas Yaakov, due to Yaakov's greatness, even if she were not Dinah.
Refer to 34:19:1:2*. See also Oznayim la'Torah, who cites Gitin 38.
According to the Ramban (to 34:12), his desire for her stemmed from her exceptional beauty (despite the fact that she was only about eight). And the reason that the Torah declines to mention it (whereas it mentions the beauty of three Imahos), is because it caused her downfall, and the Torah only speaks about the praise of Tzadikos).
Why does it say that Shechem spoke "Al Lev ha'Na'arah"?
Rashi: He pointed out to her that whereas her father had just a large sum of money to purchase a small field, if she married him, she would own the entire town plus all the fields. 1
Ramban (to 34:12): He was trying to console Dinah (who was protesting vehemently, and who would not stop crying out and sobbing).
Oznayim la'Torah: He explained to her that he had unnatural relations with her because he loved her. 2
Ohr ha'Chayim: She did not desire him (he was trying to change this).
Malbim: He now appreciated her attributes and truly loved her. He regretted raping her, which was not based on true love, rather, lust, and spoke to appease her pain and anguish.
Ha'amek Davar: He said, you need not worry who will marry you. I, Nasi ha'Aretz, will marry you!
Why does it say both "va'Tidbak Nafsho" and "va'Ye'ehav"?
Malbim: Initially he did not intend to marry her. He took her due to Ahavah (animalistic lust, due to her beauty). Afterwards, his soul clung to her due to her attributes (Bas Yaakov; Ha'amek Davar - her Chochmah and lineage), and he was Nasi.
