The inventory books do work, but they're the same as the other books, they won't take you past 10. 10 is the limit regardless of what you do with the books.
As to #1, here's a relevant link, TheMageLord has done some testing on it. Everything is the same except the bonus amounts, those were lowered in a patch after he had done these experiments to the +1, +2, +3, +4 values they are now. http://forums.taleworlds.com/index.php/topic,36707.0.html