I'm putting some SEO articles up on one of my sites, and if I want to recycle the opening and closing paragraphs (basically 15% of each overall article) would this get me in trouble in terms of duplicate content and hurt my ranking chances?
No this is no problem. Google's duplicate content filters are actually pretty lax. They are not going to penalize you if you have a small piece of duplicate content. Google is more concerned with the websites who copy most of their content or websites who just repeat mostly the same text on many pages.