Yeah i agree with most of this. The backstory is probably gonna be that Linda has dominated him in the marriage over the years and hes become used to it and became the submissive but since you (The MC) grew up, Mom has likely developed feelings for you and got confused by it, thats where i think Judy comes into that. I think Judy is the one who has pushed Linda into having an incestuous relationship with you. That line of thought has come from the very first scene in the Therapists office where Judy just bluntly asks if you have sexual feelings for your mother (and i think also Sara she asks aswell). That question just never struck right with me and its only now writing this that its beginning to click into place for me.
As for the Dad (Bob), i went down the route of using the twins to boost Dads business (i thought in the beginning it was your Dads company, didnt realise until i read on here that its part of a company) because i assume that part of becoming the dominant (alpha) male in the house is having your father pay to keep you "happy" while quite frankly fucking his wife and daughters (jeez talk about a Family affair!)
This game is good and i love Carolines story arc in it aswell as her. Shes just everything you want in a woman (shame shes CG!) The looks, the figure, the personality. Even more happy when she became financially dependent on you to keep her business afloat so yay!

I can see it now in the future updates that you will end up having a threesome with Caroline and Violet, you can see it happening.
Just the one thing i dont know and i kinda want to know. In the hallway, who the hell is the Redhead in the picture on the wall with the tattoo? Theres no character in the game with any tattoos and she isnt Linda/Caroline/Sara. Just a random woman in the hallway of your house?