Controlling File Type Association Behaviour

This is a good MS article detailing how File Type Associations work.
File Type Assoc Information

The following EditFlags Values allow the control over certain file type behaviour

eg. Allow Downloads, Prevent display in recently used program, always show file extension etc.. 

FileTypeAttributes

FTA_Exclude 0x00000001	Excludes the file type.
FTA_Show 0x00000002	Shows file types, such as folders, that are not associated with a file name extension.
FTA_HasExtension 0x00000004	Indicates that the file type has a file name extension.
FTA_NoEdit 0x00000008	Prohibits editing of the registry entries associated with this file type, the addition of new entries, and the deletion or modification of existing entries.
FTA_NoRemove 0x00000010	Prohibits deletion of the registry entries associated with this file type.
FTA_NoNewVerb 0x00000020	Prohibits the addition of new verbs to the file type.
FTA_NoEditVerb 0x00000040	Prohibits the modification or deletion of canonical verbs such as open and print.
FTA_NoRemoveVerb 0x00000080	Prohibits the deletion of canonical verbs such as open and print.
FTA_NoEditDesc 0x00000100	Prohibits the modification or deletion of the description of the file type.
FTA_NoEditIcon 0x00000200	Prohibits the modification or deletion of the icon assigned to the file type.
FTA_NoEditDflt 0x00000400	Prohibits the modification of the default verb.
FTA_NoEditVerbCmd 0x00000800	Prohibits the modification of the commands associated with verbs.
FTA_NoEditVerbExe 0x00001000	Prohibits the modification or deletion of verbs.
FTA_NoDDE 0x00002000	Prohibits the modification or deletion of the entries related to DDE.
FTA_NoEditMIME 0x00008000	Prohibits the modification or deletion of the content type and default extension entries.
FTA_OpenIsSafe 0x00010000	Indicates that the file type's open verb can be safely invoked for downloaded files.
FTA_AlwaysUnsafe 0x00020000	Prevents the Never ask me check box from being enabled. The user can override this attribute through the File Type dialog box.
FTA_AlwaysShowExt 0x00040000	Causes the file type's file name extension to be always shown, even if the user has selected the Hide extensions for known file types option.
FTA_NoRecentDocs 0x00100000	Prohibits the addition of members of this file type to the Recent Documents folder. Additionally, in Windows 7 and later, prohibits the addition of members of this file type to the automatic Recent or Frequent category of an application's Jump List. This flag does not restrict members of this file type from being added to a custom Jump List. It also places no restriction on the file type being added to the automatic Jump Lists of other applications in the case that other applications use this file type.