Book trading will most likely not be added.
You can re-roll for the book you wanted.
Eventually,you'll get the books you need.When bp is out your paladin should be at level 12-13 meaning you will have 12-13 books.Chances are you will need most of them since besides the ones on the middle column,all books can prove useful.
Re-rolling with premium is not worth most of the time and trading wouldn't change the game a lot.Basically what would you do,trade def books for off books ?Alright cool,but at one point you would also need off books for your villages so you'd need to trade again to get your old books back.
The new paladin system is good.Sure,I miss the bonfire but the new one is better overall.Dunno why you guys complain about it.
Just reroll if you want another book.