1. Yes. The baffles create a tunnel from the front bumper to the radiator. Otherwise, hot underhood air could be pulled back through the radiator.

2. The link below provides descriptions and sizes for all the factory pulleys:

First Gen Pulleys

3. I will leave this question to others. I believe some say above 220 is too hot. Otherwise whatever temp the factory set the idiot light to turn on at, as obviously that is what the factory engineers considered too hot. Unfortunately, I don't remember what that temp level is - although I know it has been mentioned on the site before.

4.The divider plate spacing is more important than the impeller. I would not change the water pump out unless you have exhausted everything else as it's a pain to do.

5. My opinion is as long as you do not have a 160 in there, you are good to go. On the other hand, if the Pontiac engineers said 195, then...

6. I would consider that a must do. Those 7 blade HD fans pull a LOT of air. I would definitely try that before changing out the water pump for one with a cast impeller.

I am an engineer by trade, and it is a bit frustrating when you put your skill into something and then the users just find a way around it...

My definition of engineering is "The study of human stupidity and the design efforts to try and eliminate it".