I don't know whether the problem is that they wanted this game to be less "adult oriented".
I think many of the points here (at least 1-3, 4 might be a different thing) are just a consequence to the decision to go "full open world" and to shift the focus of this game from the narrative and the typcial choice&consequence to more systemic and mechanical features of open world.
In TW2 the core of the game was the narrative and the choice&cconsequence. The "levels" or "hubs" were made with this agenda in mind. You can clearly see that Flotsam and Vergen and the other levels of TW2 were made with a certain narrative design in mind. The whole game was made with a certain narrative "flow" in mind, hence the act structure and the distinctive levels. That way you can make "proper" consequences with respective ambigious, hard and meaningful choices because you have full control over the narrative and the scope of the consequences. You can also quite heavily build on the main narrative.
"Full open world" changes that approach completely. First, you have a ton of extra work to do that doesn't enhance or improve any narrative strength of the series. Even the opposite is true. You naturally spread thin. You lose focus because you have to fill the world with content. At the same time you have to limit choices and consequences since you don't have the luxury of the act structure and restricted, "staged" levels anymore. People can go back and forth anytime. They can start any quest anytime. It's a vicious circle. To bigger the world gets, the less choice and consequence is possible. There is a reason why Bethesda games are so bad in offering meaning choice and consequence and complex topics in quests. It's not because they want to cater only to kids or because they are just mindless apes who couldn't do any better. It's because open world and meaningful choice&consequence with complex topics are basically two very different concepts that don't go together well. You can't have them both to the "maximum" so to say.
So why are most of the villains just evil? Well, I'm convinced that this is the case because CDPR lacked the time and rescources to flesh out their motivations. Making an evil character is realitively easy compared to making a believable bad character who has real motivations that are not just evil. The point is that real motivations need time to explain and if you want to make it properly you need a lot of time (and setpieces) to explain that. Even for a skilled and very talented writer it's hard to come up with multiple complex villains if the possibilities to transport the motivations are quite restricted from a purely technical and resource perspective. To explore the character of someone like Whoreson you'd need a lot more cutscenes, setpieces, dialogues. And still you have a whole world to fill with content, a huge world. Same is true to politics and every complex and "deep" topic. There is a limitation to that if you are restricted by resources and game design. And of course the very same is true for every choice and consequence in the game. Freedom in the way it's is understood in video games and open world games is a kind of "gamey" freedom. It's an illusion of freedom because it's impossible to create a virtual world that fully reflects all the players decisions in a meaningful and believable way. RPGs with a traditional linear or hub-based/level-based narrative and game design (like TW2) offered a good compromise between freedom and believability. Narrative and gameplay options are quite limited in video games. RPGs tend to improve upon that by giving player more options, more choices, more freedom. The point is that all of that is a game of trade-offs. You can't just offer more freedom (like the freedom to explore an open world) without being forced to make compromises. Giving the player three different choices rather than two already makes the whole rest of the game a whole lot more complex and hugely increase the workload - at least if you want to have meaningful "freedom" in your game. And that's the problem. The more complex you make your topics and decisions in a game that offers a vast open world the harder it gets to bring all the possible consequences together in a fitting and meaningful way without blowing everything off and especially without blowing the budget off and literally going on to develop the game for years. So in the end, open world kind of forces the devs to tone down the narrative in its complexity, in its sophistication and its scope, even more so than the traditional approach already does. It's the natural fight against "complexity and scope creep".
I think what many people miss is that TW2 and TW3 follow two really different approaches. TW2 was a traditional story-driven RPG that worked pretty much worked like an interactive movie/novel. TW3 on the other hand was a Bethesda-style open world driven RPG that worked as a exploration/combat/medieval life simulator. It doesn't have the same narrative focus anymore I'm afraid. So naturally, all narrative themes are actually "dumbed down" or tuned down. There are some distinctive quests in which the "old" narrative focus still shines but the big picture shows a narrative design (which contains choice&consequence, storytelling, dialogues, character design and quest design) that has to work well with the world (and not the other way round like it was in TW2).
Short: in TW3 the open world itself is the star. Narrative content only serves to fill the world with live. But it's a secondary aspect. In TW2 the narrative was the star. The game world served as a vessel to transport the topics and atmosphere of the narrative design. Levels were especially created to serve the narrative design in the best possible way. You can see it like that: for every additional small village you can explore in TW3 the complexity and scope of the overall narrative had to be tuned down by some percentage points...
I agree with everything you've explained in detail, but I think it only applies to the first part of the game, up to Kaer Morhen battle.
Whereas the first part focuses solely on open world and exploration, while the main story is getting started, at some point the main story takes over and drives to the end.
If you think about the Isle of Mists, Kaer Morhen battle, Radovid's assassination, Imlerith battle, Oxenfurt prison, other dimensions, Avalach's lab and the main battle location, they are all new, unlocked locations, specially tailored for the narrative flow. Also, even though players still have the option to go explore and finish side quests, if they're all already done, a player is able to just go through the main story to the end.
You could say the second part, or the last third of Witcher 3 is very similar structure like Witcher 2, with an option to explore.
Another observation, the first part of the game seems very efficient and tight, as far as the story, characters and open world are concerned. It's pretty obvious CDPR had enough time to work on that and get it to near perfection, minus mostly technical issues and bugs.
The second part, or the last third, feels rushed on more than one occasion, sometimes it's a minor thing easily forgotten, but sometimes it's jarring, like the lack of Triss, but also Yen content, lack of Saskia and Iorveth for 50% of Witcher 2 players, illogical and rushed end of Djikstra, Radovid never fully presented, lack of Emhyr, lack of Sorceresses screen time despite spending so much time to get them, and most of all evidently rushed Eredin fight and the White Frost but really endings as well, without any explanation or follow up.
I think most of people here would agree they don't need to do anything with the first part of the game, as long as second part is enhanced with more content. Witcher 3 can be both open world and narrative champion, and we want to have our cake and eat it too dammit
