1. The actual leaks that WikiLeaks have published have virtually all targetted the Obama administration, so I'm not sure how you suppose the leaks have previously been making the "other team" look bad. By most accounts, Obama and Clinton are on the same "team."
2a. I don't see how you could seriously suggest that WikiLeaks's behavior in this election is no different than what they had done previously.
2b. If you can find me an example when WikiLeaks published stolen emails from people within a presidential campaign, and then published those emails during the campaign for the avowed purpose of influencing the election, I'd be interested to hear it. I'd be even more interested if you could find evidence that I supported it.
3. True, they're clearly trying to reduce government secrecy by making is harder to keep things secret. But what does this have to do with my question, which was how does this help promote free dissent? And I think you're overlooking the fact that they are also undermining private citizens' secrecy, when they see fit to publish their emails.