I will suggest you to try to get all domain hosted with different content, you can hire some content writer for adding content to your site or if you can manage by yourself.
I think redirecting all domain at a single site si of not much use.
Having different sites will help you to get some adsense revenue if you put them on your sites.
Also in near future you can think of selling such active domains as they are fully developed domains with good content.

IMO there is not much use of redirecting all your domains to a single site.