It would be cool, but the Word environment is extremely limiting for what you can do with it. I've had to remove both hlsearch and block visual mode because there is simply no way to represent it in Word!! Amazing. I'm hoping I can do something about that in the future, but it will most likely involve nasty hacks - I've gone through the entire Word API and there doesn't seem to be a way to highlight or mark a section of text without altering the actual document (which kills the undo queue, etc...).
Likewise with folding. There is no underlying support for that, and so there is not much ViEmu can do. I could, for example, turn the font to a tiny size, but that would destroy the undo queue and be quite risky too.
The revision support is also just the one provided by Word/Outlook. There is a standard dropdown in Word that allows setting how to show the document (marks shown, hidden, final/original version, etc...), and it switches from crossing out the text to showing balloons on the margin, or not showing the deletion at all (even if it's kept internally). There is no way ViEmu can help with this
I apologize for the limitations of what ViEmu/Word can do, but you wouldn't believe how limiting the Word API is in some aspects, and there is not much I can do.
If you can think of something, please let me know.