you got the first one right, 0% partly right. with the vanes at 0% your fully open allowing the most exhaust air to bypass spinning the turbo turbine. so your turbine/compressor wheel speeds should slow down.

what you then need to take into consideration is any piping/intercooler restriction from the turbo to the intake. if the pipes can only flow so much air then you could be seeing 35psi on the outlet of the turbo, but seeing 27psi into the motor.