Here is a question ... Lets say you had a PR8 link pointing to your site. The sites have different themes. What PR would your site get in the next PR update? PR6?
Remember... many high PR, link selling sites are "deauthorized" by Google and Google ignore links from it.
I have had some experiences in this. The theme did not make any difference in transferring the PR. It only mad difference in SERPs.
This is true. And one indicator is the supplemental results. Check the number of cached pages of the site in google. If you find MANY supplemental results, the site is likely to lose its power. Also, check the SERP of the links on the site.