if I don't remember, I'll have to sit and start all over again, which is really bad.
Just talk with all the NPCs should be enough to remember.
quest book will be available
It's practical, but i guess we won't see it anytime soon. The game is still pretty "small" (compared to Lustful Desire) and got only a dozen+ Quests. So an ingame Questbook isn't worth being a priority.