Those are all fun and interesting, but let's face it, Lucas probably had no idea of that and it's just a lucky coincidence.
In the early scripts the Vader character was simply a "grim looking general" in the early scripts. He wasn't a Sith Lord nor did he have the Force and he wasn't the father of the good guy protagonist. It was instead Prince Valorum who had the dark side.
Again it was the name of a high school jock that was the original inspiration.
Considering all the explanations that it came from "Dark Father" and so forth come out after Star Wars became popular, I think those aren't the real reason. Trust me, I'd want it to be true so I could say how visionary Lucas was. But it's not, just like the "Hebrew prophecy on Vader's chestplate" rumor isn't true nor is the "Sun of the Sons in ROTJ SE" rumor.
It's interesting to note that one of the first things that Lucas came up with when creating Star Wars was to generate random names... first names, last names, titles, etc. He mixed them around and matched them for how he thought they sounded. You can see going through the early scripts that he will put a name on a character and then later put it on a totally different character. We only think the name is meaningful now because we've associated it with the black mask, cape and breathing for so long (incidentally, the idea of putting Vader into a breathing mask wasn't even Lucas' idea, it was something artist Ralph McQuarrie came up with after Lucas gave him the task of making some paintings to sell the idea to the studios based on his early script). Since the scene has the Vader character and his goons going through a pocket of vacuum to get to the Rebel ship, he put them all in space helmets. You may remember this painting:
Notice the hero has a breath mask as well, and Vader has a gun! In the early concepts everybody had a saber. So a lot of concepts changed over the years and it wasn't all due to some grand story that Vader had in the back of his mind, he had a lot of inspirations and lucky things enter the story as it developed.
Let's not forget this one either:
The original Star Wars was less inspired by mythology than by popular entertainment Lucas loved in his younger days, which was mostly westerns, re-runs of adventure serials, pulp sci fi and space operas, comics, samurai and WWII pictures. The whole "mythology influence" thing came later, and you could say it had an influence on Empire Strikes Back, but the idea that it underpins all of the series is mostly hype.
I mean, every kid knows who "King Arthur" is (and the same was true back in the '70s), even if they've never read the actual legends.
This is a cool site... much of the character of Vader is based on his visual development and Kaminski does it again with a nice thorough article on the subject, with great pictures: