I have a twitter feed and I see what I want to see in it. I can also follow tags here on Hubski and ignore or mute certain users that I think use that tag but don't post the type of content I think best represents it.
Also, there are no "top posts," per se. We do put a "most popular" post and comment on the community page, but that is for discovery purposes and is something we could easily eliminate if the need arose.
You could use Hubski and never even know that a "power user" exists unless you were following them. If you did get their content in your feed because someone you follow shares them or because they post to a tag you follow, then you can easily "ignore" that "power user" and you'll never see them again. What's more, you can "mute" that power user and they will never see any of your posts either.
There are tools in place to help you navigate the problems you foresee. These tools were born our of necessity and as we see a "need" for something that we think will help people to use the site more effectively, we will implement more tools. It's a work in progress and we definitely listen to our users.
It's not reddit, we're not trying to be. Reddit's been done, and it's a great site. This is Hubski. It's not about points or how many followers you have, it's about having some nice discussions with people that, in time, you can eventually become familiar with. We are a small community though, approximately 8k users and even less "active" users. If you are looking for immediate gratification from a comment or post, we aren't the place at this point. All this said, I'm glad you found us, let me know if you have any questions or suggestions. I appreciate the question.
 Not sure if that answers your question about power users gaming the "badges". My suggestion is to give the community a shot and you'll see that earning a "badge" is not as easy as you might think. It takes a while and doesn't provide for the quick return that most people that want to "game something" require.