Sand is a great sustrate to use for many fish breeds as it provides a soft cushion on the tank bottom instead of rocky gravel. It also alows for easy cleanup for you , the aquarist, as the debris from the tank will sit on top of the sand, instead of falling down in between like with gravel. It also looks much nicer in many application and the occasional quick tail lash from your fish will not kick up enough sand to cause a blackout condition. 
tho i have found that my fish like playimng with the gravel just oving the peices that they can fit n ther mouths to other locations really random acyally but as ther small fish its only my molley's tht can do it and its onlysmall peices but still funny
.Some fish are naturally found on gravel substrate remember, so not all would choke as they are used to living on it.
I wouldn't stir it, it's not dangerous to not stir it, it does good if anerobic conditions are present in the sand.