I am opening a NE facing brick veneer over 2x4 wall in southeast
Virginia to accept a larger series of windows. I plan to do the
following on the interior:

Insulate the bays in the 2x4 wall with faced R13
Cover wall with 1/2 7 layer cabinet grade plywood( gotta good deal )
screwed every 6 inches or so for rack resistance ( paranoia )
layer 1/2 inch of rigid foam, tape seams
1/2 drywall over that.

Questions:
It looks like I will have 2 vapor barriors, will the plywood rot?
Should I even worry about the foam? It will only add R3 over the studs
Can I screw through the 1/2 inch drywall through the foam into the
plywood substrate with no worries about moving seams later.

Any other reccomendations?

The foam seems an unneeded complication.
If the sheathing on the cavity face of the studs is acceptable, gypsum
board should be o.k in most situations. As I understand it, the issue
with large window openings includes anchorage of the frame to the
foundation. Local codes should note wind speed to be used for design.
TB