Grammar Question with Nor and Or

I have two questions which are similar.

In both of these examples:

20) You shouldn't ask, or inquire, or suggest.

6) Not man, nor serpent, nor a beast!

Q. is the use of nor correct or should i use “or” for both?
Q. is the use of commas correct or are they unnecessary?

I realize the neither nor, either or rule, but im uncertain in which other cases do we have to sue "nor" or "or".

(p.s. what always confuses me is that the sentence starts out with "Not" or "Shouldn't" and that makes me think its similar to "Neither").

Thanks in advance.