According to CD Projekt RED, no Items or Equipment carries over from The Witcher 2 save file.
Only decisions carry over.
Because they made the games for the consoles and they don't have previous save files they allowed for the user to choose the decisions of past games.
So basically there are no differences from importing the save and simulating one by choosing the decisions.
Since you don't quite remember what you did in those Witcher 2 save files I would recommend to you the simulation of one by choosing the decisions in-game, and you will be more aware of the decisions in-game.
No, not all decisions carry over. Only really important ones for the story. The decisions that are made in the Q&A session are:
- Did you kill Aryan?
- Did you choose Yorveth or Roche?
- If you picked Yorveth you'll 2 choices: did you save Triss or break the curse of Saskia? If you picked Roche did you save Triss or help him save Anais?
- Did you help Sile in the Megascope or not?
- Did you let Letho go or not?
Source: vg247
There are some decisions that you make in the Witcher 2 for example: (SPOILER ALERT)
If you killed King Henselt
This decision is not mentioned in the Q&A Session and there are other decisions that are not mentioned.
This sounds like the ending where Geralt has attempted to tell both Triss and Yennefer that he loves them.
Turns out, they're not a fan of you trying to seduce both of them. This is seemingly communicated off-camera, and results in the scenario you mention above, and with neither of them being interesting in continuing a relationship with Geralt.
Best Answer
Spoilers for "the Last Wish" (basically a full recap) below:
The story "The Last Wish" is about Geralt and Dandelion accidentally releasing a djinn. Danelion thinks it's going to grant his wishes, but Geralt thinks it's going to attack them. He tries to banish it using an incantation he heard but doesn't understand. The djinn roars and flies away. Geralt goes to the nearby city where Yennifer is staying, to seek her advice.
In that first meeting, he starts falling for her, while she is simply curious about him as a witcher. Hearing his story about the djinn, she plots to capture it, as it is immensely powerful and could be used to fuel her magic. She knows it will come back for Geralt and Dandelion, so she has them imprisoned to lure it back.
Geralt is talking to the guard and expresses an offhand "wish you would burst", and the guard actually does burst. This allows Geralt to escape, and makes him realize the djinn actually was granting his wishes. He has one left, and goes to stop Yennifer from trying to capture the djinn.
He finds her struggling with it, and we don't know if she has enough power to win or if it will break free and kill her. She tells him to make his third and last wish, which will free the djinn from him and allow her to trap it. He fears that she is too weakened by the struggle and will be killed if he frees the djinn. He comes up with an idea for that last wish that will also save her life, and makes it.
It works. The story does not allow us to hear the actual wish itself, but another character speculates about "tie his fate to hers", and Yennifer hears it and comments about "you've condemned yourself to me". Presumably it was something like love or binding them together. This begins their... let's call it "tumultuous" relationship which continues in the following stories.
In a humorous touch we learn that the "incantation" Geralt attempted initially translates roughly to "get out of here and go f-ck yourself". This was his first wish to the djinn and explains why it was so angry.