Looking into buying a site that is feed new content daily from yahoo, its a pr 5 site now, i want to put original content on it, not feed content, if i remove current content and put my own, will the pr go down ? will it hurt the site ?
It won't necessary go down, but it will have a negative effect b/c now everything will be new to google spiders.
PR comes by backlinks but not by content. In this case, your PR doesn't drop. Buils new backlinks and try to keep all old backlinks.
Agreed, Removing the old content is not really a good idea, although if you do it is really not going to affect the pr. Try to keep as much as the old content as you can though.