"other snaps", as in the file creator left SNAP command on? F9 toggle that off I believe.
Here are two of many web blogs with tips, I believe they will get you closer to your wish (but the free viewer has limited abilities)
http://snackeyes.blogspot.com/2009/10/autocad-dwg-trueview-2010-osnap-fix.html
http://www.cadtutor.net/forum/showthread.php?27912-DWG-Trueview-hidden-commands
Here are two of many web blogs with tips, I believe they will get you closer to your wish (but the free viewer has limited abilities)
http://snackeyes.blogspot.com/2009/10/autocad-dwg-trueview-2010-osnap-fix.html
http://www.cadtutor.net/forum/showthread.php?27912-DWG-Trueview-hidden-commands