Re: Odd choice of film (beware - spoiler included)
"...is there anything to say he is not allowed to cheer when Bamibi's mum gets shot?"
The gag and the electroshocks.
"...If he chooses to go to sleep while it is playing..."
I think having his eyelids kept forcibly open for the duration of each viewing will help here.
Seriously now, if they can force the poor sod to watch Bambi once a month, they can get away with anything!!!
;^)