Hi,
The "sheets" bug fix is included in the most recent paid build, so for now you'll have to wait until that build becomes public.
As for point 2), that's not a bug actually, it's simple when you think about it - night ends if one of the following happens:
- time runs out
- you get caught by Yuna/Kan
- you end the night yourself by clicking "end" button next to the timer
- you run out of camera battery, visible as a bar in upper right corner (this is actually your stamina during the day, so if you're low on stamina, your battery at night will also be low)
So try paying more attention during the night, which of the above happens and ends your night adventure early.
Cheers