Electric Supercharges will always be a scam. It takes power to make power with a supercharger. To get any real power from an electric supercharger, you'll need the electric motor out of a Prius, and that's not running off your alternator.
Body kits are up to you. But keep this in mind: No matter what you do to it, you'll still be driving a Maxima when all is said and done. Is a Maxima the car you want? I'm not being snarky here, I'm being dead serious. Body kits, turbos, etc will not turn the car into something else. And every penny you put into the car that isn't maint. or repair related is a penny you are throwing away. So at the end of the day your Maxima will only ever be a Maxima. Is that where you want to put your money?
If you want something else, just keep the car stock and in good condition until you're ready to trade it for what you want. Save your "extra" cash to put towards that car instead of losing it now.
Just a thought..