Yamaha DTXpress/DTXplorer/DTXtreme

As a newbie on the DTXP III two questions:
- Somebody told me that using a so called Y-plug gives the possibility
to run two pads (mono) on one trigger input with different sounds. How
do you have to do the settings for that? I assume that the trigger
settings in any case are common to both sounds, right?
- I never really understood how the switches in the
two-zone/three-zone pads work in comparison to the trigger. I´m still
struggling with the snare pad and the cross-stick sound triggering as
it only gives the cross-stick sounds when hit hard. I´d like it to
react much more sensitive.  

Anybody there to help out?

Regards        -Bongo-