Had a heck of a job getting this to working – seems like I was doomed to do all possible mistakes. First the SWD Connector on the pic is connected wrong, after that the cable was swapped around and finally I banged the wrong pins. To even make it worse I did not manage to get MCU pins working with the CubeMX, so reverted to CoIDE and old libs and voila…
At the moment I am controlling speed through PWM duty cycle and it Works “ok”. 3.3V is also working well giving me 8-28V range on the motor. The MCU is just ticking on 8Mhz using the internal clock. The next will be to control the motor through I2C, in which case I also get to optimize with motor parameters.