Apply CVS to Web Application on Linux

I'm a CVS newbie with only fundamental knowledge on CVS.
I've installed CVS on our Linux server & we're supposed to use WinCVS as client.
We already have a www directory holding the web site (PHP) & the whole directory is supposed to be imported into the CVS repository so that multiple developers can work on it.

My boss asked me to configure CVS to do the following:
1. Each developer can only check out a certain files that are assigned to him/her for edit. He/she cannot check out other files in the repository. (Because my boss don't want a developer to be able to check out the whole site & steal it away.)
2. When a developer finished editing, checked in the files, and wants to test the site, he should be able to use browser to test the result of the site within the repository. (Because we cannot allow a developer to check out the WHOLE site, he/she should only be able to test in a directory which the developer cannot R/W other files but can X.)
3. OR the developer can test in a predefined subdirectory under www, but how to enable auto-update from repository to that subdirectory whenever a check-in occurs?
4. Finally, when all developers finished their job, my boss will have the access right to checkout all the files in the repository & update (overwrite) all the files of the old site under www.

Does CVS satisfy those 4 requirements above?
How can I configure CVS to accomplish those 4 requirements above?

Thanks in advance!

I don't see where CVS could be usefull here since you don't make any mention of versioning. A well set up NFS or Samba share should do just fine since you're boss main concern (aka lack of trust) is to keep each developper from seing each others work.

Actually, my boss wants to do versioning & concurrent editing of files. I found CVS can do the thing, but I don't know how to setup access rights in the repository & auto-checkout of repository.

You could assign each develeoper a directory under www and assign them an individual CVS module (CVSROOT/.modules). In this manner only this particular user can check out thier module and edit the content. Your Boss should then recieve another module (www/) so he can see the whole tree structure.