Questions about the "Blood and Wine" expansion (spoilers, of course) (The Witcher 3: Wild Hunt)

I went through the main part of the whole component (I will not describe my impressions, I will not have enough words), and along the way, several questions have accumulated, the answers to which, I am sure, will be of interest to others.
1) What did you find while completing the expansion before the end of the Wild Hunt? What are the changes or additions to the original game? Maybe the characters' comments about the events in Toussaint?
2) If you leave additional tasks (for example, related to Vivienna and the tournament) for later, will they fail at the beginning of the final mission? And then I like to postpone the secondary.
3) The descriptions said that guests should be expected at the estate. My joy was boundless when I found Yennefer in the house (although she actually came not to visit, but to her house). I rebuilt everything that could be rebuilt, but something was quiet. In addition to your passions, does it mean that you should not expect anyone, or did you have to do something for this? And then I was already preparing for the final party in the spirit of a happy ending. And in general, I am surprised that in Beauclair they did not throw a feast on the occasion of the victory over the Bestia. Modestly Geralt became the hero of the principality)
4) Well, and the last important question, will we still have new levels of witch's armor, and new chips with skills when starting a new game?

I myself could find the answer to some questions by starting a new passage, but too long fuss, and rest will not hurt. Thank you in advance.