Before I saw Donna in WiAB, I was absolutely convinced that her mother is Leia. So I thought about the possibility that her relationship with Mario is a part of some scheme by the Zanes against the Holgersons. What I didn't know because of my lack of attention is that she and Mario have been dating for a year now. So this theory is unlikely or Vanessa has a very big patience. She still could be Zane though.
I see her as a trickster in the main story. She's connected to the Holgersons, possibly to the Zanes, and now to Nika. She will make moves behind their backs watching everyone face the consequences and clean up the mess.
Very minor spoiler of chapter 5. Since you still haven't seen it, I'll hide it.
I really hope for the possibility of starting her path in the future even if she left a bad impression on Nika after chapter 4 and from chapter 5 he starts openly confront her. Because then it's definitely will be the most intense path in my opinion.
I have the best possible theory about Vanessa so you can hate her even more. She kidnapped Summer and gave her to the Holgersons who sold her to pedophiles. Case solved.
I just love the scene where she appears out of the darkness in front of Nika. It was amazing. This, Nika holding Zara over the pool and him changing clothes in front of Vanessa are my favorite moments in terms of style and directing scene.
I'm still conflicted about Zara or Vanessa in my first playthrough. A little more and Sasha will join them.
The thing I've come to realise from developing theories of who the unknown parents is that Ocean hasn't given us anything to work with other than model resemblance (which means nothing to maybe everything). What we're trying to do is work out what happened in WiaB in effect, because we're curious. Interesting fact - other than Nick and Stefan, what male parents are known? We see Charlie, Amber and Genevieve, know of Elena, Sandra, Layla's mom, and we expect that there's a very limited number of characters that could be Ayua's mom, and that Donna is most likely a mom (of the Revera on the first team). There's a big gap of fathers. We joke that William is the city father, but at least in WiaB there are a reasonable number of male characters.
The reason we think like this is the ridiculous AVN logic that no one should be allowed to impregnate anyone other than the MC, because it removes virgin LI's from the pool (ie no virgin births implies sex was had by someone).
Until we see a character, we have no idea they exist. There are likely to be other fathers than Nick and Stefan, but currently they're not important to anything, or they're purposefully hidden. I can guarantee that most of my guesses about paternage are wrong as fun as it is to guess.
Regards complex paths: I think that once each character's trauma is explored, there will be a lot of complexity. Vic's will be emotionally challenging because there's nothing Nika can do to help her walk again, and there's Melanie in the background. Mila's issues with Mario and her parent haven't gone away (she's still the suspect seeing we haven't heard otherwise). Marla will need to have one heck of a compelling story to be a plausible LI. Sasha will be complex because of the rigidity of her social standing/upbringing. Sonya will be challenging because her parents will likely want to beat Nika into a smear. Ocean will raise the value of each story line, and people will go with what resonates with them. I don't think there will be any 'simple' relationship arc. Vanessa's will be the one where Nika feels the least in control though.
And I liked you post mainly because no one really talks about how amazing that last panic attack scene was. It's up there with the single render of Zara in the street basketball game for me - both scenes convey much more than the script does at those points.