Air management is important. I'll have a sample of a part by the end of Jan. which I think you will have left off of your list. I'll let you know when it comes in and you can check it out...it's a simple part.

I would wait on making any holes in the hood until after you have done a splitter. I like clean hoods.

The splitter (I assume will extend to the front axle line) will create low pressure under the car. The hot air in the engine bay will be drawn down under the car along with air coming in from the sides (hence the reason for side skirts).

I think, ideally, your inlet will be drawing in fresh air from outside and not the engine bay. The engine bay airflow will be in through the rad, around the engine, and out down below the car at the trailing edge of your splitter.

As long as you can supply enough air to the inlet that it doesn't need to draw on the engine bay air you shouldn't need to cut holes in your hood on a street/track car.

Hopefully you won't be seeing high IAT after doing your air management, splitter, and protecting your air inlet from the rest of the bay.

The location of a hood cut-out should be based on where the low-pressure zone is. Generally, cars have a low pressure zone about 1/4 - 1/3 of the way up the hood which is caused by the air being pushed over from the front. This is were the string and tape comes in handy. You could find out exactly where to put extraction vents for the most benefit.

//edit

Just saw Manuel's post...I should start reading DSMtuners every now and then...I had to laugh at the guy that put a SPAL plastic fan in front of his exhaust and melted it. Gee, did he not wonder why the OEM fan on one side is metal and the other plastic?