The exhaust may improve the exhaust note and overall performance, if it lowers exhaust backpressure. I'd make sure they've done flow analysis on the muffler, and can prove that it actually improves performance. Marketing-speak will tell you what you want to hear, performance curves will tell you the truth (as long as the company does the before and after tests under the same exact conditions of air intake temperature, ambient air pressure (way back, some unscrupulous marketers would test a car in the 'before' state at a high altitude on a hot day, then test it in the 'after' state at sea level on a cool day), etc.
As for the performance chip, it's essentially making your bike run richer than normal. That's rarely a good thing, unless you're looking for out-and-out performance (and if you are, buy a bike with a bigger engine).
This scooter, if properly maintained, will hit 77 mph (although the engine's above the red-line), and will easily cruise at 65 mph. That's plenty fast for most purposes.
For your money, if you want better performance from this bike, the weakest points are the variator and the clutch, performance-wise. Putting slightly heavier roller weights in the variator should give you a better launch, and slightly weaker return springs in the clutch should give you better low-speed response.
