I feel like the droprate for pages is ok. I may not get the specific pages I want though lol. I always get an axe or a greatsword page..when I just want staves
As far as I know you always get a page you haven't learned yet, so it shouldn't be too hard to complete. You'll get it eventually even with terrible RNG, which is more that I can say for many of the other aspects of the game (damn you, trophies! ).
I haven't completed them yet so I don't know what happens after you get them all. Aren't they account bound by the way?