I know that pretty much everyone here will say a CAI will help, but how much?
Slightly noticable.

i'm assuming that it will give a SMALL increase in MPG. I've read that you will aslo be able to notice it by the sound of exhaust and the sound of the intake. What kind of performance should i expect? I'm assuming not a whole lot...
You will hear the supercharger compressing the air..it'* a whining sound. No change to exhaust and usually any MPG is offset by HFS (heavy foot syndrome)

Another thing i'm considering is a smaller SC pully (seems to be the thing...)
Is it really just as simple as swapping in a small one? You would have to make up for the difference in the belt with a larger idler pully somewhere wouldn't you?
It'* very easy. You could use a smaller belt or a larger pulley.

If thats the case, and it is that easy, how dangerious is this for the engine? Its a DD and I don't want to turn it into something that needs to be worked on all the time.
My DD has them on it and it'* as reliable as the day it came off the factory line.

How Does the smaller pully'* affect your gauges? does the boost gauge reflect the increased boost?
With increased boost will i Hit a limit somewhere all the time?
More boost shows on the boost gauge the same way more fuel shows on the fuel gauge.

Anyhow, i'm starting to think about all of this early so i can be informed about what i intend to do. Sorry about the load of questions and sorry if a lot of theme have been asked 1,000 times before. I couldn't find what i was wanting in the search... Thanks again!
The beauty of the forum...no one gets flamed...questions get answered.

If you're thinking of putting on a smaller pulley, then you will want to do that CAI first, complete with heat shielding so you are really drawing cold air. The faster SC will want more air to gulp and the CAI pipe and K&N cone filter will help to provide that.

You will find a snowball effect happening.

Mod #1 leads to Mod #2 and so forth.