Folders cannot have unique permissions  in this release. List/library is
the lowest level  where permissions can be assigned.

Can we have a some Freindly Name associated with the Files we upload  in Documents & Lists ??

You mean something other than the name of the file that you uploaded? You can always add additional fields to the document library and change the view to show those new fields. Just have to make your users  are trained to update those fields when they are adding/updating files  in the doc libraries.

I have created a additional column "Friendly Name" in my Document Library at the time of uploading new file it asks for this Friendly Name which is mandatory for a user  to enter. But now i want to access files  through this Friendly Name for eg.

I want to list documents which has 'SharePoint' as a "Friendly Name" in Document Library in MyWebPart.

Please let me know still i am not able to state my problem.

You mean showing up in the document library view? Instead of the document itself?

I think you’ll want to have the document name appear to retrieve it (it’s linked ot the document), but you can modify the view (same page you added the new field) to display the new field.

You can check out www.doclibplus.com if you still want folderlevel
permission. Do mention my name if you make enquires...

As for listing which has 'sharepoint' in your webpart, you can add a
document library webpart into your page and set the filter
accordingly.

Folder level  permissions in a document library are not available OOB. IIRC, there are some third-party web parts that will do this – as to their quality/effectiveness, I can’t speak.