Ecumaster classic aux and stepper pin questions and general

Hi!

Ecumaster Classic, 1JZ engine

I have a few wiring questions, some more general than others. I don't want you to just spoon feed me answers, I genuinely want to know why it is the way it is. These are last few bits I am missing on the pinouts before I make a schematic.

ECU grounds are crimped together and all go to a star point on the block. What's a better practice, to crimp them closer to the ECU or closer to block?

Do I need pull up resistors for fluid pressure sensors?

Do I need flyback diodes for AUX outputs for VVTi, MAC valve and relays? If yes, do they come on the load side or ECU side or anyhow?

My stepper outputs are empty, I will use them to control relays. Can I also use one for a warning LED light? Says up to 1A. The way I read the manual I can choose whether a stepper motor pin works as a ground or +12V, is that correct?