I think tapping to get the main menu should be pretty easy. I've thought for a while that dragging with the stylus would be great for panning the image. I'm not sure how to have both panning and zooming available at the same time, since the gesture would be the same. Which do you think would be more useful, or do you have an idea of how to do both?
I'll probably have a go at this tomorrow, and PM you when I have something to test. Thanks for offering to beta-test for me.