If impact windows are required they are required for every window and door in the house.

Well, they're not required by code. I'm trying to be a smart shopper and not overkill on the window purchase.

All you have to do is decide what direction the wind will come in a hurricane (and do not forget the direction reverses as you move across the cyclone).

Well if I am not mistaken a good part of the uplift and damage from a hurricane is to the backside of the house (which is where Design Pressure is from) so I don't believe i would only look at the direct the storm comes from.

Impact windows are not there for uplift, but from flying debris that can easily punch out regular windows.

While the design pressure may be on the lee side, the flying debris damage is to windward.

Flying debris is correct but the debris would break out the window causing the envelope to fail which will cause the uplift. The whole premise behind the straps for the house to the foundation, the rafters strapped, the sheathing, the windows installed with clip or straps is to prevent the envelope or exterior of the house from being compromised.