Give it a try and report back.
edit: Wow, HN has changed. There was a time when experimentation was encouraged here.
You can see in the video how hot the CPU runs. If I remember correctly, a 20°C temperature increase halves the lifetime of electronics. "Normal" laptops tend to stick around 60°C-70°C. Apple apparently decided that halving or even quartering the CPU lifetime compared to that is fine.
That said, most MBA CPUs probably spend their CPU lifetime closer to idle. It'd be interesting to get temperature numbers for that. Still, it's worse than it could - and IMHO should - be.
The entire overclocking community would disagree with you.
Modifying the thermal & power management profile is very difficult as it would require reverse-engineering the firmware.
I guess a temporary hack would be to mess with the current sensing circuitry to make the machine believe the CPU is drawing less current that it actually is and encourage it to give it more power.