Finished. last thoughts
1) Enjoyed the basic mini-game, and the Asylum is well worthwhile as an event building. Was able to get a level 9 with no diamond spend, but only by doing way too many book quests (for a measly 5 candies for each of the first 4 quests)
2) The Librarian quest overall was very frustrating. Despite logging in each day, and playing to avoid pumpkins and only go for 1 example of each type of book, never got 1 full set of books. The drop rate for silver and gold books is quite (too) low. Several guildies had the same problem, unable to even get 1 full set of books despite daily plays. I can see 1-2 persons having bad luck in a guild of 50 as reasonable, but not 11.
3) Rewards for books were poor, so avoided going for extra copies of books until the last 4 days (when I had pretty much given up on getting the final silver and gold book i needed). And then only did enough extra book quests to get candies for 1 more tool kit.
4) For me, pumpkins also gave very uninteresting rewards, so skipping them to focus on potions and some books will be the strategy when/if I play on live servers.
5) overall, an OK event, though overly time-consuming with all the book quests. If completing the Librarian quest could be made just a little bit less time consuming ( i.e. improve the drop rate for a full set of books) that would be a much more reasonable use of time to get extra tools, than doing really boring and repetitive books quests for only 5 candies a shot.
Or, as an alternative, slightly increase the amount of candies received for logging on each day, and for completing main and daily quests. Even 5 extra candies a day from each (10 more total per day) would probably be enough over the course of this long event.