Why does Reaver get away with all he did in Fable 3?

Solution 1:

Out of universe, crappy writing and Reaver being a developer favourite that Lionhead wanted to keep for a sequel. But that's off topic and not the answer you want.

In universe, there are two reasons. First, he's wealthy and has a huge amount of political power. If the hero tried to have him executed and/or confiscate his industries, he has more than enough resources to rebel. Whether or not he would win is irrelevant- the result would be another civil war which would leave Albion too weak to defend itself.

Second, he's centuries old, hasn't aged and is a Hero. Notice how tall he is? He's capable of earning and spending experience and has probably been doing so since Fable 2 where he was already the Hero of Skill. One on one, he's more than a match for the player.

Solution 2:

My guess is that it's because he is a person of power. Both physical, political, and financial power. I really think the only way to take someone down from that high up is by killing the SOB... But I'm not sure that would work, considering the only game he's not in is Fable 1, suggesting something of an immortal nature... cough Dorian Gray cough

However, in the storyline of the hero, (or you, the player), Reaver's ahem "habits" are a bit less important than saving all of mankind.