Just some brainstorming:
- line height: it could be customizable in the paper background definition and the be used as a line size
- panning page: i don't see anything else than gestures for that. Since the 900 has a screen smaller than the surface, it should be reasonable to detect a gesture that starts 'out' of the screen. If it happens such a case, the touch can be interpreted as a gesture and not a drawing (as the browser works for the cursor mode). With a gesture from top to bottom or viceversa, the screen could be panned exactly half of its height. Could it be a reasonable solution for note taking?