One more step completed - a bare-bones string value editor (yes, for both editing existing and adding new string values):
Now, the bad news is that the OpenNETCF.org Smart Device Framework won't cut the mustard for the editing part - I will have to resort to P/Invoke for getting at the value data types correctly. I knew that P/Invoke would rear its ugly head rather sooner than later. Anyways, nice learning project.
(1) Registry Editor for SmartPhone
(2) Registry Editor for SmartPhone, List View