ACK! THE ROOF: TO VENT OR NOT?

Reader beware...

Nuances of this roof:

• Rafters (2"x6" ripped to 6" "exactly") are running parallel to the width (not length as is standard)
• I'm planning on using two pieces of 2 5/8" rigid foam between the rafters, (potentially) leaving about 3/4" space for venting (holes in rafters and blocking could allow for venting from side to side of the house, OR from eave through rafters up to ridge)
• There is 2"x6" diagonal blocking (not 6" exactly) with an 18 gauge metal strap nailed into it
• I'm stubborn about not wanting to use plywood for sheer strength
• the vapor barrier on the roof (bitchathane/ ice & storm most likely... .... ....) needs a consistent uniform surface to lay upon; Therefore, if I do vent at the top, I imagine I'll need to sandwich a few layers of corrugated plastic (same stuff ridge vents are made from)
• It is possible to vent the longer side (seen with the diagonal in place) but not the loft side (which will have a hatch roof that pops up)
• There will be small windows at the loft level to open for ventilation

IF NO VENTING
PROS: I just want to put the roof on, enough already

CONS: worried about mold developing in ceiling

IF YES VENTING
PROS: the roof is vented! longevity
CONS: pain in the neck, less space in loft's head room

BOTTOM LINE:
I have to make a decision. The rain is coming.