Google latest Webmaster video.
More pages does not equal to better ranking. Whats your view?
A lot of great content pages will most likely rank higher than few pages with great content...
You can redirect the 'juice' of your own pages with links to one important page at your site and thus make that particular page rank higher.
I think to some extent that indexed pages help out with a site in that it guides more people to it. I mean, it would be possible to get other parts of your site to come up on Google, so I do think that other pages get indexed automatically. For example, whenever I made a blog post, that post was searchable.
Really good quality of posts is what will rank you faster.
As long as each indexed page is of quality, the site should rank a bit better because of it. But, don't expect this to be some shortcut or something.
I don't think so, that indexed too much pages is not the sign of ranking. It may be possible that you can get some traffic increase due to lots of pages but does not means that if a website has lots of indexed pages get ranked easily.