What's the difference?
My understanding is that "Nothing" will sink the touch event into oblivion so it will actively do nothing, while "Ignore" will let it propagate and do whatever the zone might already be doing on its own (say, a page turn).
That's correct.
Terms like capture and propagate are too jargon; almost no one without the specific domain knowledge would understand what that means. Perhaps "pass through" instead of ignore?
@Frenzie: I like it :). (Because I did have to scratch my head for a while to wrap my mind around it the first time I encountered it ;)).