Shechem acted admirably

Well, not precisely, but that is the general theme of an explanation by Rav Yonasan Eibeshitz in Tiferes Yehonasan:

He cites the midrash, cited by Rashi, that vayaaneha means shelo kedarka. And he explains it based on the calculation that Dinah was only seven years old at the time. Since there is an assumption (discussed elsewhere in the gemara and midrash) that a woman cannot become pregnant from first intercourse, and since there is a separate assumption that a ketana can become pregnant but that the pregnancy would be fatal, that the second bia was shelo kedarka was for her benefit. Since he loved her, he wanted to avoid to possibility of her becoming pregnant and dying. And as to the kidnapping her and sleeping with her, he thought he was acting in accordance with law. Since he was chieftain of the area, there was droit de signior, or something similar, granting him the right to sleep with any betulah he wished. And he compares with a Betuel, who was called this because he was boel all the betulot, as the head of the city.

Incredibly creative midrash, and entertaining; but I don't think this is what Chazal intended. Two obvious difficulties with this is that if we look at the gemara he refers to (Yevamot 100a) about ketanot making use of a moch, the time to start is from 11 years and a day, but earlier than that -- say, seven years old -- no conception is possible. Another obvious difficulty is a midrash Rashi cites a bit later, on וכן לא יעשה, which is that they had fenced themselves off from arayot, which Rashi elaborated as לענות את הבתולות. So the assumption is that they would not have the right to do what Shechem did, even according to their own laws. This, aside from a general thematic shift from what seems to be the intent of the midrash. Still, you have to admire the creativity and skill at play here!