Keyword proximity is an onpage seo factor. If you have a certain keyword, or a keyword phrases featured over and over in each page, this keyword will be targeted by the search engines. This is important, but very minor. IT will give you nothing based on that only.
Useless, It is better to avoid these type of technique. Because it is not necessary that your all pages reflect to one or related keywords.If you want to promote your inner pages then Using Interlinking technique is good or Make use of deep linking directories and Social Bookmarking.