Is it possible to hide metadata fields based on group?

We would like to have a clear view of which assets have been approved in which workflow and by whom. Because many of our assets are at different points in approval, by many different teams it is essential that we can see which approval has been completed in the properties of each asset.  Would havin...

In the Assets section, when creating an asset you can see all of these options in the drop down. We would like to remove them so that only 'Folder' and 'File' remain. 

How can we change the default 'Create' dropdown menu to only include 'File' and 'Folder' ?  

In our Asset meta data we have some drop down fields which contain 'Approved' and 'Not Approved' options.We would like to limit who can select the 'Approved' for a given field based on group membership. How can this be done? Thank you