The opportunities to find success through a failed roll will be present in the game. If I remember correctly, Swen talked about it in this interview :
https://www.youtube.com/watch?v=S5__muccL1cFor the rest, it's hard to say. I wouldn't expect much capacity to improvise in a way that affects NPCs and dice rolls, mostly because that seems like a really complex system to implement. Those situations might exist in the game (we already know you can poison goblin grog and affect our environnement in a meaningful way) and Larian's systemic approach might actually make it possible to some degree, but I just wouldn't expect us to be able to improvise and adapt in all the ways D&D makes it possible. On the other hand, it seems to be the kind on system the people at Larian like to make and it does fit with the way they are making this game, so they might just be able to offer us something in that regard.