Thanks everyone for the advice. After some tests of my own, I have been cutting thick card stock no problem and not even a candle sized fire. Details are follows:
Cutting in piles of 2.
Size of the cuts are about 10"x10"
Thickness .02
Speed 500
Power 55
number of passes 2
putting 4-5 magnets on top of them so there is no air between the paper
These setting have proved worthy, not one fire mishap and no char marks on the bottom cut!