Are there any charging issues with changing out the crank pulley for something smaller I am assuming. You guys are trying to drive the accessories slower correct. To me if this messes with the charging(at idle) this mod is a waste.

Basically for NA any exhaust mod or intake mod is good to do. The better you get air in and out the more power your motor will make.

Actually; a good catback system alone could easily give you close to as much TRUE gain as the three mods that you listed combined.

ehh.. i dunno how bottleknecked the g35's exhaust is, but almost any production car can benefit from a better suited and proportioned exhaust.. personally.. i would do away w/ the cats and use oversized straight through glasspaks/resonators.. We used that alot on turbo honda's and all motor cars and it kept them quiet, but the gains were phenomenal