well it is a problem sometimes when a paysite is closed and if you running review site you will have to remove the old pages, there is no much you can do Google or Yahoo wont punish you badly for removing some inside pages as long as it won't be a routine and will happen once a while, one more thing you can do in a future is to work with more established sponsor programs their paysites rarely getting closed cause of massive webmasters ammount that reselling them,
i am not really sure how 301 & 302 redirects works
but in worth case scenario just redirect deleted pages to index using 404 redirects
as for those pages PR abviously it will be lost ,its not such terreble just wait for PR update and you will get the new review pages with PR , my suggestion is actually concentrate more on getting better listing not pr
thats just my thoughts