Hm, about keyword density:
For example:
http://www.v7n.com/forums/ - page title "Webmaster Forum" - and I think main keyword for this site is "webmaster forum". Density - 100% !
http://www.seobook.com/ - page title "Aaron Wall's SEO Book.com" - I could guess that his kw could be "seo book" or "aaron walls seo book". Density higher than 50%.
I could go on. Almost any search on Google for more competitive kw shows many sites with repeated kws in their titles. All others at least do not meet 3% requirement.
How did you came with this number? Why not 4% or 5% ?