Just another mistake to add to my “knowledge” collection :D. Regardless, to answer the additional questions… TIM1 pins are just “taken” (2 of them used as USART1 and the last one as general input to report some DRV8302 faults).
I can use other USART interfaces and reroute the PWM inputs of the driver to TIM1 pins just fine. Should be matter of 30 minutes.
So if I get it right, if I use for example PA8, PA9, PA10 (TIM1 channels 1, 2, 3 respectively), it is still fine to use the TIM1N pins PB13, PB14 and PB15 for other purposes as long as they’re not PWM generation?
I am unfortunately quite low on time (and definitely not skilled enough) to try and fix that myself in software. Still, thank you @dekutree64 for posting the alternative solutions. I will probably just take a minute of silence for the money I spent on this version and then redesign/reorder 
.
One more thing that comes to my mind before the redesign. Do you guys use STlink or just serial for uploading the code to STM32? Do serial prints work just as easily with STlink as they do with serial line?
Thanks for all the help !