Reader: Was it right for Simeon and Levi to deceive
and attack the Hivites?
Mesora: It appears so, as Ibn Ezra states, they took counsel from their other brothers, and their father Jacob only rebuked them for generating hatred from others, and not for their killings.
Reader: If Shechem alone defiled Dinah, then why should others suffer for Shechem's sin?
Mesora: Perhaps the fact that the other inhabitants did not oppose Shechem's actions displays that they too were worthy of punishment.
Reader: In what way was Dinah defiled?
Mesora: She was raped, and held captive.
Reader: Finally, what is the significance of saying Shechem was the most honorable of his household?
Mesora: Perhaps this indicates that since the most praised person of that city was very corrupt, it sealed the fate of the entire city. It also teaches that others would not oppose him. It may also indicate what gave him the gall to violate one of Jacobís children - his elevated status fed his ego.
I have further information for you.
You asked: if Shechem alone defiled Dinah, then why should others suffer for Shechem's sin?
I answered: Perhaps the fact that the other inhabitants did not oppose Shechem's actions, so they too were worthy of punishment.
I had just come across a commentary on Torah, Rashi, who supported this (Gen. 29:28):
"And if you will say, 'what is in our hands to do, G-d will punish the many for the (evil) thoughts of the individual, as it says, "Lest there be a man or woman...[who goes astray]' ...and afterwards it says, 'the [other nations] will see how the land [of the Jews] is destroyed. [My words: this means that based on the former, i.e., the sin of one person, the land will be destroyed, as this follows immediately in the Torah. This is posed in Rashi as a question on G-d's justice, it seems unfair to punish the many for the sins of the individual...Rashi now continues] "But a man does not know the hidden thoughts of his neighbor and we can't punish him for hidden matters [that we know not] for to G-d our G-d are hidden matters, and He will exact punishment from that individual, but the revealed (sins) "are to us and our children" to extinguish the evil from our midst, and if we don't bnring evildoers to judgment, G-d will punish the entire community." (End Rashi) This teaches the exact point I mentioned.