You should totally try WebsiteAuditor from SEO PowerSuite. It`s perfect to audit a site and focus on all things on-page - it provides comprehensive analysis (covers all factors ScreamingFrog does), but it doesn`t only show the errors, but explains them and provides tips and recommendations on how to go about them. For content optimization it analyzes organic competitors for your keywords and provides keyword-usage statistics and page-specific recommendations.
Here`s my fav guide to the program (even better than specific learning materials):
http://www.link-assistant.com/news/65-ways-to-use-website-auditor.html