Google tanked my site - what could be the factors?

Although my site has not been banned it has stopped receiving traffic from google as of October. This site is a year old and I mostly market it via directory submissions(which I purchased a package of 5000 links over 20 weeks from an SEO company), submitting articles to ezinearticles.com and then syndicating them using distribute your articles.com. I also only use articles on my blog that are unique and I submit them to social bookmarking sites using onlywire and social bookmarking demon.

Here Is a example site:

I bring this to the warrior forum before contacting google be because due do the recent updates it could prove as a interesting study. I have researched all of the things that google may have penalized me for which are the following:

1. Content above the fold
It has even said online that google is penalizing for this and as you an tell my site has a significant header and also google ads before the content.

2. Spammy links
The fact that distributeyourarticles.com and social bookmarking demon are automated tools, this could cause my site to contain spammy links out there that I may not be aware of.

Should I be using google's disavow tool? I don't think this is realistic unless I change my SEO tactics going forward...which seem pretty white hat to me

3. My site is about a year old with about 60 posts... I have heard that new sites sometimes benefit from a google bump and that google has corrected this and taken away this traffic....I doubt this theory because I have a site that's over 10 years old that has been hit as well.

4. Duplicate content
Even though I pay for original content I don't know exactly how google classifies this

5. over optomization

I hear that if all your anchor text contains keywords then you may be hit for over optomization. Some people are recommending using non keyword anchor text sometimes to avoid this.

Based on this information I think it would be a pretty cool experiment to see if I can pinpoint causes before going to google....and who knows if they'll even point it out to me.

Any insight would be appreciated.