The whole issue with electronics and computers is so complex that getting definite answers rather than opinions is difficult.
I'm building on a budget so need to be aware of what is peripheral and what are necessary precautions.

Shielded cables and grounding the chassis does seem to be a necessity to prevent problems later.

An emergency stop facility, limit switches and circuit protection also are in the necessary folder.

That said I want to keep it simple so I'm trying to find the compromise between necessity and unnecessary componentry.
Thanks for the responses Evans