The point is that for each of those high profile situations, it is very easy to look up the other party(ies) involved using publicly available resources. Spacey's victims have their own wikipedia entry regarding Spacey's sexual abuse allegations.
The George Michael case is literally from 1998, 26 years ago. It took me like 3 minutes to find the name of the officer involved. And many of those articles are from between 1998 and 2001, so it's not even like this is because of the exploding popularity of the internet.
My point is you'd have to be aware of Marcelo Rodriguez and role in order to link him with the George Michael case. Nikos isn't the George Michael in the reporting. In my theory he's the Marcelo Rodriguez. He's the mistress in the relationship. And the George Michael or the other examples I mentioned aren't even good ones, as they're much higher profile examples from AAA-list stars. A random businessman who embezzled 10 million dollars isn't on the same level als Lady Di.
My point is two people having an affair publicised on don't always get equal coverage in the press. Names of mistresses do get forgotten and get impossible later on. When Britney Spears cheated on Justin Timberlake with professional liar Wade Robson it wasn't known to the public.
I'm suggesting Seferi was a high profile businessman who went to jail for embezzling money. It may be so that Nikos stole a bit of that money to help him start up his business and he took in Seferi's daughters. That's how Nikos came to prominence later on in his career. But he wasn't at the time of the affair. When coming up to prominence he's lived the life of a bachelor to cover for his true preferences in romantic partners: men.
Regardless, I welcome the speculation, but I'd want to hear how this would further the plot or character motivations. If Nikos was Seferi's lover, then that's implying that maybe this story is about him trying to get revenge on Toska with Seferi. But the two don't really seem to be working together. Nikos is getting married not to Seferi, but to Elena. Nikos without a lover makes sense why he's crafting Andrew into a lover. But if he's in love with Seferi enough to take care of his daughters and also help on a revenge plot, it genuinely doesn't make sense to me why he's also this hyper fixated on fucking Elena.
Bear with me, as I'm a bit of a scatterbrain. I'll just type and hope you can follow me here.
Joel is like a triple spy in the story. He works for Elena (p788), Nikos (p1142) and Toska (p672). He's the nephew of Seferi (p1196), which is interesting as on p672 Joel says a relative of his used to do business with Toska, which didn't end well for that relative and he had to take a job with Toska as a way to humiliate his family. So, I think it's safe to say Joel is the son of Seferi's brother who had to pay off the fraud and embezzling of 10 million dollars.
Because he's shot (by Seferi, without wearing gloves, which is interesting), Elena suddenly starts trusting Seferi and Joel whom she knows are working together. But we know Seferi did it to regain her trust (p1203). So we know they can't be trusted. Why can't he be trusted do you think?
You're asking for a motive. Sophia shares an interesting motive. If Nikos gets married (or renews his vows), Seferi knows where Toska will be so he can be arrested. Toska humiliated (Joels words) Seferi's family. That's revenge.
If Seferi was romantically close with Nikos in the past he knows his type. Nikos has been a bachelor for a long time, never committing to a woman. If Seferi works with one of the daughters he has a close link to one of the women feminising Andrew into Elena, the one who helped establish a look for her. Eva is the person Marina is in contact with when she's in Crete (p169), serving as a wall between her and Andrew to single him out. Sophia later avoids Marina (p831) to keep her at a distance. In Crete, Marina is in need of rescue when she's being stalked by Gjoka, who happens to be married to the woman who drugged Andrew earlier that started the whole feminisation process (p805). James then serves as a distraction for Marina later on, even though she says he isn't a threat to Andrew.
So the way I see it (right now), Seferi wants to take revenge on Toska for humiliating his family after he embezzled money. Gjoka cooperates to take the top step for himself, even giving a gun with his own prints to frame his boss. That revenge is taken by having someone marry Nikos, who happily obliges as he has a woman tailor-made for him by people who know his preferences. He likes his women to be former men. That's something only a former partner of his would know.
I feel this ties most of the story together. Angeliki serves a questionable role as someone who took Elena to the beauty salon where she suffered a scare (p524) without Eva and Sophia. This scare was big enough for her to forget all that's happened there, including her ability to speak English and causes her to think in Greek. This happened the day before Elena woke up after her surgery; she feels she was talking to her doctor "just a minute ago", so I expect we'll get a flashback of this big scare later on. Maybe Angeliki played a role in it, as she's the person picking Elena's swimsuit that further drives a wedge between Andrew and Marina as Nikos can't stay away from Elena in it (p1221).
Are there any loose ties I haven't covered yet? Feel free to disagree, but I feel this story would give mostly everyone a logical motive and reasoning to do what they've done so far.