Won't submitting articles to article directories penalize your own site? (assuming you have your articles posted on your site) How does this work? And what's the benefit of writing your own articles for your site when you can just take a "free article" and use that?
What if someone else copies my article and posts it somewhere, like on a forum? Years ago I wrote an article on a controversial financial topic for a site I used to have and still to this day (5 years later) people repost that article on forums. If someone copies information from my site, that pretty much nulls any quality content that was on my site.