Metadata Navigation Tree will redirect to a document library instead of to a Wiki Library

I have added the following to my EnterpriseWiki.aspx page layout:-

<asp:Content id="Content1" runat="server" contentplaceholderid="PlaceHolderLeftActions"><wssuc:MetadataNavTree id="mdnt" runat="server"/></asp:Content>

Currently the metadata navigation tree will showed up and will work correctly, but I am facing these two major problems with it:-

1. When the user clicks on a term in the tree it will redirect to a document library and it will show “add item” link which will add a new document. But is there a way to redirect to a Wiki page library and allow the “add item” link to add a new Wiki pages instead of a document.

1. The Metadata Navigation Tree will be shown ONLY to the following group of users:-
   1. Site administrators.
   2. Site Contributors

But it will not be visible to site reader, although site reader are able to view the pages and they should be able to see and use the metadata navigation tree?

Thanks in advance for any help.