Sure, I would agree that under your definition of "free choice" we do have the capability of obeying or disobeying God.
"Even in scripture, this doesn't always happen, though. God didn't force Saul back into obedience."
God didn't force Saul into obedience because He had selected David to take Saul's place. David was annoited to be king long before Saul went to see the witch of Endor.
Why didn't he compel Saul? Certainly He could have done so.