Some interesting bits from this article.
https://spidersweb.pl/2020/06/cyberpunk-2077-questy-pawel-sasko-wywiad.html
About the story length and general quest structure
Cyberpunk's structure was built on the foundations set by the lessons we learned from our work on The Witcher 3. The Witcher had main story as it's core with several subplots branching out of it. That was the basic structure, which we called a wheat spike. In Cyberpunk we added another nonlinear layer to it in the form of the subplots that serve as a quests, which can be triggered in a various circumstances. Those quests are not set up in a linear fashion. We are using an internal system, so called token system, which decides on whenever the game supposed to give you those quests.
That means that even I couldn't tell you in what kind of order those quests will trigger for you, because the game itself will decide on that based on your current progress. Of course we are still holding the reins and decide upon what kind of conditions need to be fulfilled for that particular quest to trigger, but the process itself is very difficult to explain. The game has the most complex structure that we ever did.
Looking back, in case of The Witcher 3, some players and journalists had an issue with the main plot being too long. Around the battle in Kaer Morhen and right after it there was this feeling of upcoming finality, but it ended up feeling too stretched out. That was one of the issues we wanted to avoid while creating Cyberpunk's main story. That additional time we got by making the main story slightly shorter, we spend on the subplots.
So in the Cyberpunk's structure we have this wheat spike, which serves as it's center, the main storyline with different subplots surrounding it, which can be triggered in a various ways. Those subplots allow us to do something that we have never done before, they change the main plot of the game and they are doing that in such a way that you may not even finish the main plot, but still finish the game and get a completely different epilogue then the player with a different lifepath who made different choices, met different characters and formed relationships with them.
The game's nonlinear nature is present on several levels. Because of that, it's hard for me to tell how long exactly it will take for the player to finish the main story. Regarding of how many subplots we prepared, at this moment, looking just at the story content that has been handcrafted by my team, they are equal in length to the main story, even a little longer then that. Everything depends on the playstyle chosen by the player.
When people play the game as a Solo, they tend to finish the game faster then players who prefer more silent approach and, for example, avoid killing people, which means their playthrough will be quite longer. That quest inside All Food Factory, with the Maelstrom gang, Dum Dum and Royce, which you were playing through, offers 12 different paths and those paths vary in terms of length. Depending on your chosen path, the quest will have a different length and because of that it's hard to answer this question.
About whether you can finish the game without killing a single person
Oh yes, very much so. The most important choices in the game, all the bosses and elite enemies - there is always some way to avoid a bloodshed. Sometimes violence and enemy encounter is unavoidable, but it's not like you are forced to tear your opponents apart, but also you can't avoid the combat entirely - however you are able to fight in such a way to neutralize your enemies without killing them and finish the game this way.
About lifepaths
Interviewer: So how much of an impact the choice of our character upbringing have on the story - is it just a window dressing and some additional dialogue options or does it also opens up an alternate paths?
Paweł: When you choose your lifepath, as a player you define who you are. As designers, we need to be aware of that throughout the entire experience. At the start of the game you will have a completely different quest, start your adventure in a different place and meet Jackie in a different circumstances.
At some point the story narrows down a bit, then depending on your backstory you will get an access to a quests, which you wouldn't get with different lifepath and that's the first difference. The second one is that you have a certain options during the quests, which are unique to your lifepath. I don't know who you were playing as...
I: Corpo.
Oh! When you talked to Meredith Stout, have you tried using your lifepath related dialogue options?
I: Yes, I noticed there was an additional option there.
And who did you met in the end of your quest?
I: I told the gang about the virus.
OK, so you decided to betray Meredith. This is when your lifepath becomes the most visible, when you interact with other Corpos your knowledge allows you to choose the options unique to your lifepath. That has it's own consequences later on. That's just one example of how the additional option in a single scene can open up another branching path for the entire quest.
I: So if I chose another lifepath, I wouldn't be able to make the quest play out this way?
That's right. You encountered people from the Corp, so your Corpo knowledge made a difference, but I can tell you that Nomad has an access to something that Corpo does not. As a Nomad, you would be able to obtain the convoy's signatures, since Nomads specialize in robbing those - since they themselves live in convoys, travelling with their cars and bikes. As a Nomad you know how to steal the convoy signatures and then you can use that information to trigger another path.
As a designers we are always looking for a ways to provide the player with roleplaying options. Those different possibilities don't give you a completely different ending, but by sticking to this particular lifepath, as a Nomad you will be dealing with people like you.
It's the same for the other lifepaths - they all have their own, custom epilogues. What's important, is that you can change your path. As a Street Kid or Corpo you can start working with Nomads, play through the game this way and end the game as a Nomad - but if you start the game as a Nomad and then end the game as a Nomad, you will receive an additional paths and parts of the story. It shows that there are many layers to that.