Wow; take a few days off of the forums, and come back to.....whatever that theory is.
It is an interesting mind exercise but there is nothing in the story pointing towards it, and I'm not buying it in the slightest.
1 - Not that type of game. That would be 100% pure *enter those three war starting letters here* by anyone's definition of them. We can, and have, argued about whether someone having a past counts as *that*, but there would be no debate if something like that occurs now.
2 - This isn't intended as sarcastically as it sounds, but there is really no other way to put it.
In any type of story, written/vn/graphic comic/screenplays, there are side characters that are necessary for the storyline. You talk about the 3 brothers, which we only saw two of, but why not the lawyer as well? Or Meiko's parents (forgetting their name at the moment); dad seems a bit picked on, maybe he wants to be the filling in a Meiko/Abby sandwich while the mc "calms" mom down a bit? Lets not forget our friendly waiter from the first dinner with Becky & Abby...or Bob....anyway...
Just because you see someone in a scene, especially a scene created to explain a sudden financial windfall or that moves the story along, doesn't mean they are magically part of the main story.
It is way more likely that we will see the sister that is responsible for Jess's death, than see the brothers again.
I'd keep going, but this is long-winded enough.