Welcome
a manual tranny swap has been done before, but its not a good idea, it cost a TON of money and with fab work its a pain in the ass, and only a certain tranny can be swapped and it costs mega bucks.
as for the supercharger, yes you can do that. Tons of people have done that on here.
READ THIS BEFOR EVEN STARTING! : http://www.grandprixforums.net/safel...car-17482.html
as for exhaust, im my opinion dont do it, these cars sound like butt with mufflers on. The stock exhaust sound good when you have headers and other mods and is still quite on the freeway unlike aftermarket mufflers that give you DRONE. Plus the stock cat back has no flow issues when it comes to modding, so no need to change it.