[Yamaha Jog C Coolstyle] Introduction to gentle tuning

Hello,

I have recently started riding Yamaha Jog C Coolstyle. As surely many before me, I now wish for more speed and I started thinking about tuning. I see that ideally I would be better off with slightly bigger ride like Axis or Zuma/BWS because of their larger power, wheels and passenger-carrying ability. Alas, this is not an currently an option because it's more expensive, I already got one and I need a driving license for that.

The thing is I am not mechanically inclined (maybe mechanically challenged, even); I want to go on long trips out of town on my scoot and I wish for it to go long without failing. I can buy the necessary components and find a good repair shop to do the job, but I can't do anything myself.

What "safe" modifications can I do that will not significantly impair the scooter's reliability, or maybe even increase it? (e.g. now it takes 100% power to go 60 km/h and I'm afraid going for long rides like that is a bad idea, but if it will be taking just 80%, it might work more reliably, right?)

What modifications are better be done with each other?

1. I have an idea that using an alternate CDI is bad for reliability (they say Red Daytona is the "best") because it just takes the cap off the engine's rpm.
2. What about tuning the variator: if we let the gear ratio go higher, it shouldn't impair reliability, should it?
3. What about changing the exhaust: I was told that [url=http://www.leovince.com/en/products/leovince/exhaust-systems/scoot/sp3]Leovince SP3[/url] is good (I would appreciate the noise profile and looks that don't show off). But how exactly does exhaust influence engine's work?

3a. I'm offered a good deal on Yasuni Z exhaust. They say it's miles ahead of Leovince SP3 and works fine with stock engine. It's shiny, but I think of spray-painting it black. How well you think I'll be off from reliability point of view?