Separate bibliographies for one document

“convert to unformatted citations” IS the way you unformat to temporary citations.
    
In Word 2010, the “format bibliography dialog” is on the Endnote ribbon, by clicking the “drop-down” box highlighted in yellow in the attached image.  The dialog has the default setting of { }, which you would change to .  

No - if you “unlink” the fields, you also get rid of the hyperlinking.