Production quests should autocomplete
Yesterday's guild quest involved, for me, something like 10 hours of production. I have no problem with that. However, as it chanced, I was not at home or online when it finished producing, and when I did get online later it was past the daily deadline.
There's no reason I can see why such quests should not autocomplete once all the requirements are met. Having to click "done" to get the reward is annoying and unnecessary, and in the case mentioned cost both me and my guild, for something largely beyond my control.
So, the suggestion is: make quests (including daily and guild quests) auto-complete once all requirements are met, pay out the reward and notify the player by mail. Even if this meant that adventures also auto-complete, that should not be a problem - just means you need to be vigilant in loading your spare troops before launching the final attack; something most of us do as habit anyway.