Hi Josey:
Have no fear about your rafters collapsing, just look at any historic structure that has survived the test of time an you will see just nailed on rough boarding over the rafters, in many cases on very large buildings with very high roof peaks.
the only case that I can recall is of the rafters being lifted out of their seatings at the bottom due to a vicious storm some years ago. Even partly exposed frames will withstand high winds.
According to what you say the rafter seatings are let into the plate approx. 2", this in itself after pinning will cause the whole rafter network along with its boarding to be very rigid, and no doubt stay with the frame when the wind picks the whole structure up and carries it away!!
NH
