Its natural to be a bit bummed about it at the first few months or weeks because the sleeping habits you have are turned topsy-turvy, but then you'll adjust in time. Just relax after work and chill.
I would not send food back unless the manner it was sent to me was insulting. I'd graciously accept it but send back a note of what i thought about it. It seems a bit unethical if i send the chow back...
I think the best way to present sushi is by slicing it thinly. Arrangement counts as well plus the sidings should be with green stuff like seaweeds or something yellow/ orange. The fish should simply be FRESH.