I guess since you've been charging, you've already set the lithium type in user setup to lipo (3.7v)? Once thats done, storage setup asks for a charge rate and a disch rate. Depending on the voltage of the lipo, the charger may need to charge (voltage lower than stg voltage) or discharge (if voltage too high).

I wouldn't use the same rate as you do for charging, use a small charge/disch rate like 1amp for both. You don't want a high charge/disch rate. You want a low charge/disch rate so the voltage comes down slowly and evenly to the storage value and shows littel voltage recovery after the charger stops. This will help with cell balance too.

As far as cell diff goes, the better quality cells usually show less than 5mv - my Neuenergys are like this. My Turnigys show 10-15mv diff in individual cell voltages. So it depends on the lipo a littel as to what you should expect. Just observe yours and see what they are like. It'll prob stay that way until they get close to needing replacement.