First of all, replace all of your "Demo" text on the site with actual real text. (Notable in the footer)
Secondly, Get quality threads with good descriptive replies going. (Make multiple accounts if you have to)
With that said, I highly suggest not applying for adsense with a new forum. Most forums these days get denied unless they are getting a decent amount of traffic. Create a blog with some articles (Even if the blog is on the forum itself) apply to adsense with that blog. After which, you can add any site you want to your adsense account.
For the policy violations, does it say which violations occured?
This makes me think you have another adsense account? If so, then this also may be an issue.
You are only allowed 1 adsense account.