Well, it looks like I might just be talking to myself here...
But maybe there are others who are interested in this same question, so I figure I'll continue to post what I learn elsewhere. So far, all I have found is this youtube video, which seems to show the kind of conflicting input I was worried about
:
https://www.youtube.com/watch?v=rur3NxOx9IY
At about 1:18 the user places their hand on the screen and continues to "scribble". When they lift their hand away from the screen, a mark is visible. They then circle that mark and draw an arrow to it, and finally they make a note about that mark.
I copied the text describing the video to google translate. It auto-detected Japanese, and spit out: "I tried the handwriting function in. For Palm reduction is not attached, it contains the line and get the palm of the hand."
Now, this may be an inevitable issue with the dual-touch interface. On the other hand, the user posting the video may be unaware of the proper way to avoid this. They place their hand on the screen before touching the stylus to the screen--maybe if they had done it the other way around there would be no problem.
...I see that ereader-store.de is temporarily out of the N96 dual touch--so there must be some in use out there! Anyone reading this with knowledge, I'm eager to hear about your experience!
Thanks