Could you, please, explain the literal and metaphorical meaning of "ramification" in this passage from The Great Gatsby?
"The transactions in Montana copper that made him many times a millionaire found him physically robust but on the verge of soft-mindedness, and, suspecting this, an infinite number of women tried to separate him from his money. The none too savory ramifications by which Ella Kaye, the newspaper woman, played Madame de Maintenon to his weakness and sent him to sea in a yacht, were common knowledge to the turgid sub-journalism of 1902."
From the quote, Nick notes that Dan Cody became rich by pursuing metals: gold, silver, and copper. He was "physically robust" but "soft-minded" indicating that he had a soft spot for women and/or he could easily manipulated. Ella Kaye was a woman who saw Cody's weakness and evidently tried to exploit it. Nick says she played "Madame de Maintenon" to his weakness.
Madame de Maintenon was Louis XIV's second wife. Their marriage is agreed by historians to have occurred but at the time, their marriage was never made official. The reason for this is likely because of the differences in their social statuses. This was certainly a "rags to riches" story and one Gatsby himself might admire were it not for his greater admiration for Dan Cody.
The association between Ella Kaye and Madame de Maintenon recognizes the "rags to riches" aspect because Ella received all of Dan Cody's inheritance, even the $25,000 promised to Gatsby. Gatsby was left only with what he learned from Cody:
And it was from Cody that he inherited money—a legacy of twenty-five thousand dollars. He didn’t get it. He never understood the legal device that was used against him, but what remained of the millions went intact to Ella Kaye. He was left with his singularly appropriate education; the vague contour of Jay Gatsby had filled out to the substantially of a man.
Commenting on the association between Ella Kaye and Madame de Maintenon, Nick (via Gatsby's story) is focusing more on Ella Kaye acting opportunistically, greedily, even dangerously. "None too savory ramifications" implies something sinister, that Ella Kaye became romantically involved with Cody, not out of love, but out of greed for his money: an opportunistic, and therefore sullied, version of the rags to riches story -- which eventually succeeded when Cody died. The ramifications were that she eventually got Cody's money while it was Gatsby who, in the last five years of Cody's life, was much closer to him than Kaye was.
Evidently, Kaye's manipulation of Cody (or of driving him away to sea, perhaps dangerously so, as noted by Gatsby) was common knowledge in the lesser known presses during that time. In other words, it was known by some that Ella Kaye used Cody to get to his money. The ramifications (consequences) of she and Cody's relationship were that she inherited his money.
That is the extent of the literal meaning. If any possible metaphorical or extended meaning was implied, by Fitzgerald or as an interpretation, it might be that, having received no inheritance from Cody, Gatsby had to make it all on his own. So, the ramifications of Ella Kaye's actions reached Cody and even Gatsby himself. And as Gatsby became wealthy, met Nick and reunited with Daisy, ramifications continue to branch out and affect others.