1. Yes
2. Yes
3. Trying to look through Geralt's eyes, not mine
4. Nope
5. All the way Triss in TW1 (Shani was in the same role there as Triss in TW3 - option just for the sake of variety, against any common sense)
6. Yes, watched all possible cutscenes out of interest in my first playthrough (Keira, Cantarella, etc.), but reloaded it. Second playthrough is without cheating
7. Only Ciri's opinion could matters to some extent
8. As in the story
9. Yes
10. Yes, to some extent, as I said. It's not like I would change my romantic choice only because of her opinion, but I definitely would consider her words and do some serious talk with her.
11. Hell yeah
12. It's a canon, BUT the core of any RPG is a freedom of player's choices
13. Pretty much yes, because of the variability of the story paths in the games - ending could be canonical if it's single, definite, not then there are 36 of them.
14. Fan-fiction, but exceptionally good one. There's no room for something like "separate alternative universe"
15. No, but it's still great
16. Yes
17. As Geralt - not always, it's not obligatory. From my personal POV it's more often.
18. Always, she's not doing anything without a decent reason
19. Pretty much the same, never caught a thought that she's in big mistake in the games (but there are a number of such moments in the books)
20. Too much of them, needed to be specified
21. No
22. Yes