Hood Scoops.

1. Actually, you should be congratulated for knowing you were in over your head and asking questions here on FABO rather than take the knucklehead approach of drilling holes in an otherwise good hood and wondering later if some expense and frustration could have been avoided. Smart approach, young gun.
2. My experiences with cars dying in the rain have to do with bottom feeders (e.g. Olds W-30, Honda, Toyota...and by extension anything that has the engine air intake at the bottom of the car.). When driving a bottom feeder, avoid standing water. Even if the intake is several inches above the water, water can be sucked in putting a damper on ignition festivities. What can happen is that the tires and front body work can setup a bow wake that covers the intake. The bow wake can also be picked up by the fan spraying the distributor and coil resulting in loss of forward progress at some point.
3. The purpose of the scoop is not so much to ventilate the engine compartment (see air extractors, 2d gen Trans Am front fenders.) as it is to provide a cooler air supply to the engine than is available under the hood. Since cool air is more dense than warm air, it makes more power all else being equal. As far as making a scoop functional, go for a look you like then apply sound principles to make it work. e.g. Shaker scoops work better with a drain; avoid putting a the breather hole for a functional hood scoop over a brace; make sure you are presenting enough area into the air stream.

Have fun, enjoy the ride, welcome to FABO.