As the family depart their home pond, they head towards the rising sun, which suggests they are travelling east rather than south.
When the elderly heron takes the pan and places it in the water, it is clearly empty. After the Mallards have got in, Mack pulls out a partly eaten fish that wasn't there before.
This is the sort of humour cartoons have practised since time immemorial.
Domestic ducks raised on farms are generally unable to fly.
Artistic licence. Films are not intended to perfectly reflect reality.
The fire extinguisher would not have been triggered by the weight of a duck, as most extinguishers are fitted with a safety pin that must be pulled out and two handles that have to be squeezed together with far more force than a duck could exert to prevent an unintended discharge.
Artistic licence. Films are not intended to be exact reproductions of reality — this isn’t real life, it’s a cartoon.
Clouds are essentially just water vapour, so the ducks couldn't have donned them like bath bubbles as they flew through them.
It's down to artistic licence and a suspension of disbelief — they wouldn't be able to do that 'in real life', but this is a cartoon.
