Weak Homepage = Supplemental Index?

I'm starting to get my urls indexed on google now that my sitemap is functioning correctly. However, every page except my homepage is in the supplemental index (over 700 of them). What are the factors that will put you in the supplemental index? Will a weak homepage hurt the rest of your pages?

Anyway, if anybody could mention a few common errors that get you put in the supplemental index, i'd appreciate it.

What are some of the things you have done recently other than install vBSEO?

Please submit your site for a critique.

Make sure you donot include showpost urls to sitemaps and you replace showpost links with permalinks so they will not be accesable. It will prevent your pages fall into supplemental result.