1. Will a page with a rank directly contribute to your site (which the backlink points to) as long as it is indexed in Google? 2. Will a page with a rank contribute to your site if it is not indexed in Google?
I don't believe a page not indexed in Google can have any pagerank since Google either doesn't know about it or has banned it and therefore it cannot have any effect on your page. I'm sure someone will correct me if i'm wrong.
1) An indexed page with PageRank will generally contribute or pass some PR to all of the pages it links to. 2) A page that displays toolbar PageRank that is not indexed in Google may not have any PageRank. You should consider the possibility that toolbar PageRank may not present a current or accurate value of a page's PR. Another thing to keep in mind is that PR0 may not always mean absolute zero - it very well could be that the page has a PR<1.
yes they can have. I have many sites and 50% pages are not cached but they have pr 2, 3 Pr. At the time of link building you have to check for it's cached status, no flow, no index status. If a page's Pr is 5 and that page has 100 outbound links then the page will pass low Pr value than page which is having 20 links on a page.