I think it would be nice to have an event, even if only once a year, where you can unbind a limited number of books per character.

Сегодня я (в надежде решить проблему со входом, которая опять появилась после выхода последнего обновления) удалил версию с сайта и установил версию из плеймаркета, и у меня слетели настройки панели на одном персонаже, хотя у меня стоит галочка "хранить единые настройки". Однако на этом же аккаунте на остальных персах настройки так и остались прежними. Что вообще произошло? 

There are a couple arguments against it.   Firstly, making books unbindable would drop their value heavily in the long term. The reason they keep their value is that they are useable only once. Books keeping their value is important for F2P players, since it's one of the main things that allows people to make a lot of progress at once. It also is important for the game in general. If books we're suddenly cheap, there'd be far less reason for anyone to do dungeons, to open chests for keys, to do guild events etc.   Second risk with that is scamming. Trading/selling/sharing accounts is against the rules, but it does happen. Currently, support can help people quite a bit, since a big chunk of an accounts value is bound within talents and books. Making books removable would mean that people can get stripped of almost everything they've worked for due to one mistake.    Thirdly, it is kind of in the nature of the game that certain classes get to shine more than others after each rebalance. Right now it's not that big of an issue, since building a new char to match that isn't easy. However, if you made books, the most expensive and hardest to get part of those chars, easily movable, people would just transfer them to whatever class happens to be the best at the time, creating a pretty stale environment class variety wise.   Personally I think that these downsides outweight the benefit.

как можно на полном серьезе писать про рандом как способ заработка? 

Такой же кек был в обсуждении новых талов зимы: он выдавал в духе "ну, с книгой отража тал нормально работает". Благо, уважаемые разработчики переделали талы, а не оставили тот рандом на рандоме, что был предварительно. Впрочем, ачивки сами себя не заработают.