6% powerless seems reasonable. The CVT transmission does not have a torque converter compared to conventional auto gearbox and the torque converter contributes to most of the loss.
CVT also less gears, typically only 2 pulleys and a belt compared to other gearbox with many many gears.

6% should mean the maximum efficiency of the transmission, probably during cruising. However during acceleration(varying gear ratio) the CVT would have much lower efficiency.
For example the mitsubishi lancer using CVT has gearbox overheating issues when driving spiritedly(hard accelerations, deceleration and then accelerating again). However I don't think it would have issues being driven at top speed for a period of time.

The 205Nm torque is the measurement directly from the engine. Same like BHP. Bigger figure looks better on the spec sheet.

What he is trying to say that if you mod your engine to produce 10Nm more you would probably mess up the transmission.