Here is a current update on this situation.
The new version (947875) solves the primary issue with the Windows 8 3D graphic crash.
Fusion works in all modes unity, single, full windows.
There are still three areas of concern:
... Office 2013 graphics are noticeably slow
... External monitors can still cause the crash when switching them in/out
... When system enters sleep while in unity, mode confusion or the crash result.
Fusion is still finicky entering unity and refuses often.