@metaljay Great to hear you have got it working!
@Plasma I would definitely recommend a level convertor - in fact I am surprised you have not killed the GPIO lines with a 5V signal. On the crashing, have you checked the voltage on the DCDC module under load because I have had some Pis crash without explanation if there is excessive voltage drop on the power supply. May be worth testing for a couple of weeks with a known good USB power supply to rule this out.
@Plasma I would definitely recommend a level convertor - in fact I am surprised you have not killed the GPIO lines with a 5V signal. On the crashing, have you checked the voltage on the DCDC module under load because I have had some Pis crash without explanation if there is excessive voltage drop on the power supply. May be worth testing for a couple of weeks with a known good USB power supply to rule this out.