I wish I was a Witcher, immune to STDs, wielding a sword. The Game is quite graphic, although I will have to read the book... Is the game a straight retelling of the book?

Was the game subtitled The Wild *unt before it took on Wild Hunt?

No you don't. Having a fantasy and living the fantasy are two entirely different things.

Not at all. In fact, there were quite a handful of vocal complaints on each release about how the game got the story wrong. Keeping in mind that the whole point of the game is to give you the experience of Geralt's life without putting you on rails completely, I'd say the games are very good about keeping the characters generally similar to their book counterparts, and the setting is at least as close as Peter Jackson got with the LotR movies.

The books are a good read. Well, the English-translated ones. I can't read Polish.
EDIT: typo