Interesting thoughts (may you all have peace!)... but I have a question for you, dear PSacto (the greatest of love and peace to you, dear one), please, if I may. You stated:
That Cain found others in the "outside world" isn't really an issue since it is stated that there are other people besides the imediate family of Adam and Eve:
And then quoted:
Cain said to the Lord, “My punishment is greater than I can bear! Today you have driven me away from the soil, and I shall be hidden from your face; I shall be a fugitive and a wanderer on the earth, and anyone who meets me may kill me.” Then the Lord said to him, “Not so! Whoever kills Cain will suffer a sevenfold vengeance.” And the Lord put a mark on Cain, so that no one who came upon him would kill him. Then Cain went away from the presence of the Lord, and settled in the land of Nod,east of Eden.
I am trying to understand where, in the verses quoted, does it state that there are other people besides the immediate family. I get that it's implied... based on the way "we" think, but I would like to offer that I have received from our Lord that that was not the case at all but, rather, that Cain was concerned about the "law" of vengeance, which was carried out BY the immediate family of the victim. Based on that law, ANY of Cain's OTHER siblings... as well as his parents... could have come across him later... during his or THEIR travels... and avenged Abel's blood.
The reality of this is based on the fact that Cain became a "fugitive." A fugitive is one who runs away/hides from those seeking him for some crime. Here, the only people who KNEW of Cain's crime... and the ones against whom, by extension, the crime had been committed... and thus, the only ones who WOULD be seeking him... would be members of Abel's immediate family. Which were the SAME members of CAIN'S immediate family. Thus, the only ones who had a RIGHT to AVENGE Cain's crime against Abel... would be members of CAIN'S immediate family: his parents and/or his siblings. Likewise, the only ones who would be SEEKING him, therefore... would be members of Abel's... and thus Cain's... immediate family.
And THIS is what Cain was protesting: that he was being sent out, unprotected... to be hunted and killed by his immediate family. Their avenging Abel's blood would be only a matter of time: sure, Cain would wander, but he would also be stalked during. How could anyone live that way, knowing that their death was imminent as soon as an avenger caught up with him? And there was no such thing as a City of Refuge, so there was no where for him to run TO.
The Most Holy One of Israel showed Cain MERCY, however, by prohibiting vengeance against him. In this way, should his parents/siblings ever come across him they would have to allow him to live.
We can't have it both ways, dear one: how can the "people" of Nod be different... yet serve the same God as Adam/Eve/Cain? And "they" had to serve Him, yes, if JAH's decree that no one touch Cain were to apply to "them"? Be effective? Otherwise, why the mark? What would such people care about some mark from JaHVeH?
But there were no such people: Cain was being protected from his immediate family, both his parents and his siblings, as later shown in provisions of the Law Covenant... where is was either upon the PARENTS to stone such a [murderous] child... or upon the "avenger" (a sibling) to kill him. ALL, however, were "released" from this... due to MERCY.
I hope this helps and, again, peace to you!
YOUR servant, sister, and fellow slave of Christ,