SPOILERS BELOW, read at your own discretion
Each quest starts out strong but ends in the most half-@assed way possible. Literally none of the 3 missions with Vivian get any explanation. Her introduction and being a more developed personality with the first mission being really interesting won me over. A reliable veteran agent suddenly goes completely nuts? There could have been so many reasons and not giving one is such a wasted oppurtunity. There could've been some drug addiction, or him forced to go undercover while trying to root out an inner spy, so you're sent after him by Vivian to neutralize him, before he gets his evidence published to JKK? Instead what've we got? We find this agent and he's just hostile from the start, we kill him and nothing is explained. There's nothing in his room, a diary in his desk or on his body where his writing gets more derailed due to his mind being slowly consumed thanks to the deprivation of a certain drug that made him that effective to earn his status among JKK. So now that he lost his supplier or whatever, knowing what is to come, he choose exile and slowly gone mad.
Or an even better route that connects more to the plot: details of him being choosed to discreetly perform an inside investigation, as Edstrom was led to think that there might be a possible double agent among the company. Eventually he got busted in front of the double agent too early, overstepped his authority by doing something that's against the morals of the company getting him formally fired within the company, or with his cover blown, making him and his employer conclude that returning to HQ or even going out in public with now Coretech being after him was a bad idea (while being secretly still in contact with Edstrom). During his investigation, an oppurtunity arised, but with a steep price of loosing his cover, crippling the whole operation... But he took the risk and managed to uncover something that might provide enough evidence against the agent's agenda. After tracking him down, he could inform you about his suspicion on her and you could choose to eliminate him without coversation or hear him out and eventually let him go. Later upon Vivian's disappearance, On the way out, we could meeet Ola (assigned to keep an eye on you being such a sudden freshman in these times and getting along surprisingly well with Vivian) who would suggest to keep this confidential until they gather further details and waiting for the perfect time to make their move.
Later, Ola could've included the reports of this missing agent in his explanation to the player after the 3rd mission, so at least we could have something. Instead of nothing. Would that be too much to ask? Literally it's nothing more, than just adding a few dialogue lines... but the difference it would make would be huge. Then Ola just adds on to the player's frustration when he has the ordacity of getting all upset for being asked to provide at least some explanation. And that's what made me frustrated, it's not just that things turned to the worse, you just have to accept that you're not even get filled in on the details. We've never know why the agent turned batshit, who's the guy he was fighting with at the bar (a possible counter agent from Coretech set to tail then neutralize him and steal any evidence he gathered) and for what reason and what made him change so suddenly from a focused veteran agent to a crazed up maniac attacking everyone on sight.
Why start a questline, building up interest, when you're not going to develop it further than it's beginning? Because that's what the first quest have. Just a start and nothing more. It ends without a warning or explanation and in it's current state, it meets the requirement of being just barely functionable, so the player can move on to the next one. Such a waste.
No explanation on the second either. Who are the kidnappers, who were the hostages, nothing. At least I was not as interested in those questions, if that makes it better or worse, that's another question. Also, why any of this is JKK related? I thought we're gonna have a betting heist, or some arena beast breakout... I mean their main profile is Arena matches and it's broadcasting. Why it's them doing the rescue? When there's a hostage situation, the law enforcement's special team gets in. That would've be Praetorians. If JKK got contacted by a general in command of the rescue operation to ask for disabling the security security of the complex so hat they could move in, that would've made sense. They found out that with it, there's a formidable opposition and in order to avoid unnecessary casualties, they had to resort employing outside assistance - from JKK who know a thing or two about broadcasting and also surveillance, also happen to be in for the easy money. You could even totally drop the hostage rescue idea and say that they don't say much, but for what is known, a warehouse got stormed by an unknown mercenary organisation... So you could totally link some quests together and say that the building is the warehouse where the third quest happens for the Praetorian Security. Minds would've been blown for people in their second playthrough. And again, zero programming required, all it would take is just changing the dialogue and the quest would suddenly make sense.
Third one is just to make the players mad. A sick joke. Suddenly you are presented with a character that's actually surprisingly developed compared to what you've ssen recently, actually had a backstory, fun dialogue, everything. It made you feel that yes, devs can do good writing with enough effort. Only to have that shattered in the most sadistic way possible - cutting off the flow with an event happening outside the players view. I know it might be a little self centered to complain about this, but seriously, how could you do such a grand build up, making us partake in interesting and fun interactions which leads the player to a mission that the two attend together (which is basically what everyone wanted at that point), engaging in conversations about each other and sealing it with a promise. Literally everything is done so that the ending can be as frustrating as possible. Really a huge middle finger from the devs.
Now let's forget that we're here as gamers first and foremost, and inspect Vivian from a different perspective. I'm not working on HR, but I know as much that people like Vivian are fun to have around in workplaces. This type of personality can be annoying when it feels forced or falsely acted, usually when it's used in occasions when it seems out of context or when as a tool in order to achieve something.
But if it's genuine, effortless and without any intentions while not being overused, even if the person is downright ugly, these kind of people can be major reasons for other coworkers to return back to their work every day, especially in such places like police, ambulance or retail. Even if things get busy and stressful, they can make the day easy and workers can leave with energy from the fun they had. Especially when it get's tough, the harmless positivity they radiate can forge work relationships, exactly because after a certain point, these connections can only get stronger in giving and receiving reliability and humour in times of hardship.
Vivian was that person, and it's a shame they erased her out of the game the way they did. If the devs want to destroy her so much okay, then she should've just betray the player in the third mission, making it seem like she actually lured you into a trap, plotting on you falling down to be eaten by mutants and revealing her true identity through well written lines on the radio aterwards when you ask for her help. Saying that she found out how your meeting with Bogdan really turned out who might eventually got tracked down by Coretech slightly before you finding him. Already late to save him, before death he tells you the password of his safe that he kept from the enemy with the real evidence. So she knew he had to find a way to eliminate you so she made this trap. She's indeed the spy, this whole setup would fit well with that. Of course, against her efforts you fix the elevator, climb back up only to be facing her crossbow - leading to her demise while with her dying breath she admits that she was not all happy that things lead to this... Some players would still be heartbroken, but that would've been a proper goodbye to an NPC, that at least had run it's short, but full course.
This questline had so much potential and if you think about it, making it one of the most memorable one in the game wouldn't take much effort at all, mostly just writing some additional dialogue lines. Too bad they just made it one, if not the worst and most undeveloped quest in the game leaving the player hollow and cheated.
Sorry if my criticism seems kinda harsh, but I tried to back it up with valid reasons and providing possible solutions to the best of my ability.