A really good way to move into editing for a mystery shopping company is through a referral by a scheduler/editor at a MSC for which you currently work. Based on quality reports already presented to their company, you would look like a good candidate.
A Closer Look has a note on their Home Page, available to all shoppers, that they are now hiring both schedulers and editors. Both are part-time independent contractor positions and both are work-from-home positions.
Good luck!