Hi there,
I'm the founder of Fireviews.com, and I've responded to a similar question on these forums in the past. You might want to check my account history and read up on those threads, because a lot of other people chimed in as well.
But anyway, posting your Youtube videos on Fireviews is perfectly safe. It's just a social network, no different than Facebook or Twitter, but the focus is on getting you viewed and getting discovered. There is no risk of being banned on Youtube after using Fireviews.
As Michael pointed out above, Google can be very finicky about AdSense accounts though, whether it's on your Youtube video or on a web page. They have been known to cancel AdSense accounts for no reason at all, with no warning. But there is no reason that Fireviews would have any impact on your AdSense account if you post a video with ads in it. It is perfectly okay and within Youtube and Google's terms of services to post your monetized Youtube videos on Fireviews or any other social network.
Do let me know if you have any other questions, and feel free to use the contact page on Fireviews.com to contact me directly.