Auraninja
Eh, ragazzo!
The "challenge" part of the game is paying debt and collecting all the museum specimens/paintings.Remove that punishment, and you remove a large part of the game. It's the "challenge" of the game, if you prefer.
I don't think adding a "vacation mode" would do much to go against the intent of the game. New Leaf has the Beautiful Town Ordinance where you don't have to water everyday, and I believe villagers move less often with it in place.