In several - To pass PR your page/site must either link directly to the other page OR have a redirect header (permenantly moved) to the other site. In the first case, google needs to index the page in order to see the link... in the second case your site will no longer exist as it redirects (I guess this will pass PR, and prevent the cache... but say bye bye to the sub-domains)
I am not sure about this. I have several pages with the meta tag <meta name="robots" content="noindex,follow"> which are not indexed in Google, but show pagerank in the foolbar. If Google implements the "follow" in the meta tag as a command to distribute PR--just as rel="nofollow" in a link is implemented to NOT distribute PR--the pagerank should be distributed from these non-indexed pages to other pages.