so, you want the end user to register, to upload a file, and then you want an admin to be notified and before the file will be displayed on the public list, have the admin either accept the file, or decline the upload.
automatically updated... not sure what yo mean, but the public list would be updated automatically with each new file upload...
then, for the page after the end user clicks on the link on the public list, that would have the description on it, then a download counter, a rating, and a end user comments...
I think thats what you want, now, it would better for the user to fill out a form that the user would have to put a description of the file and a link to it so you, the admin, can download the file, evaluate the description, maby test it out a bit, then if the admin thinks the file is good or what not, the admin can upload it him/her self.
I hope you understand what I am saying.