Power rolls off up top because the turbo runs out of airflow up there. If the idea is to maximize power under the curve, add torque to the midrange where you can really use it, then it's perfectly tuned. If you want to limit performance down low to "fool" yourself into thinking it's making peak HP at peak RPM there are a couple ways to do it.
1) Pretend your redline is 5000rpm.
2) Press the gas pedal down more gently going 30% at lower RPM slowly ramping up to 100% at redline.
As far as traction goes BMS is currently working on a boost/traction system for the vehicle to help with launches. Especially from a stop. They may program the car to make less boost than stock in 1st gear, slowly ramping up to full boost in 3rd, or something like that. Whatever it is they will make it fully user adjustable. I'll post more details when I have them.
Mike