I have mixed feelings about this event.
It seems a bit out of place to use this as a Halloween event. Yes, you can win some nice prizes, but also some annoying ones - depending how you build your town(s)
The link with the quests is a good thing, just to re-activate the use of the quests - which are beginning to be repetitive and sometimes way too expensive to use, especially if you look at the 'gains' possible? Just look at the percentages or time you gain (e.g. defense).
I am, at this point, not convinced about the use for a Halloween event. Yes you can exchange ideas within your alliance, but some give big gains, whilst others recipes give you a simple thing. Maybe equalizing the received gifts might be a positive thing.
So, neither positive nor negative... So probably something missing which I cannot point my finger at (for the time being)