What is your low-voltage cutoff set to on your ESC? The lower you go on volts the more prone to puffing the pack will be.
If you are going to use the pack within a week or so then storage mode is not critical, and if you do have the discipline to watch the pack on the charger then yes, using balance mode and pulling it off at the right voltage will work fine. On most chargers, if you start a storage cycle with a pack that is discharged it will be quicker than starting with a charged pack since chargers typically always have much higher charge rates than their discharge rate.