Mardon and EdHorny:
You guys really don't understand how power output works.
The gist of it is that the engine puts out torque, and that's it. That's the only measure with any meaning. The HP is basically a conversion of that torque on the RPM scale of the engine.
So in essence, to increase the HP output without increasing the torque figure would require an engine that would keep increasing power as its RPM goes up, and then removing the rev limiter.
Unfortunately, turbo engines usually do not work like that, so there would be no benefit in upping the rev limiter, especially the ones with turbos as small as the TSI motor has.
However, about 50Nm of torque increase (it translates to about 210 BHP) should be safe for this gearbox, although I wouldn't get it on my car without an explicit warranty.
Clearly not.. I'll do some reading and get back to you.