Len,
Welcome to the forum.. I can make a few recommendations when from my gigging experience that may help some of your issues..
First, get your brain unit onto a separate stand, and off the rack. My unit used to go blank during a performance, and putting it on it's own stand has done a lot to take that away.. I had it happen to me only once during the last gig, and I think it's because my monitor was right next to it.
Secondly, the vibrations from a loud performance can wreak havoc on the triggering. Try to keep the bass rig and any subs FAR away from the kit. I tend to check the trigger indicators while the bass does soundcheck.. If I'm seeing anything light up, I up threshold level and retest the offending pad(s).. If we're cranked up, sometimes it's tough to get the sensitivity right. Another killer could be the crosstalk settings, which can cause as much problems as they solve.. but I'm not going to stir that worm drink tonight.
Anyways, hope my rambling helps..
~D