Also, the Bible doesn't say God "endorsed" it. Just because it's in the Bible, doesn't mean or imply that God wanted it to happen.
I whole heartedly agree with this statement. The example of Jacobs sons taking revenge because of what happened to Dinah their sister is a clear example. In vs 30 of chapter 34, Jacob was troubled because of his sons actions. It is sometimes hard to read between the lines, as the bible in these accounts tends to get straight to the point.
Looking at the whole picture helps us to see that such blatant disrepect for the leader of Gods people (Jacob) at that time had terrible consequences. What Shechem did was a dishonor, not only to the leader of Gods people Jacob/Israel but a mark of disrespect and mockery to God himself. Whether endorsed or not, the outcome was that this whole unfortunate episode now made Gods people stand out amongst the cities throughout the region (Gen 35:5).