I love working with ACL as they have great shops and I get paid on time. I too wish they had more shops that were not just reimbursement only.
As for the Secret Shopper issue, I think that's wrong that they will charge YOU the stop check fee. You have to get paid; it's not your problem that their check got lost in the mail, although neither is it their fault. However, they are the one with the bank account. That said, is there any way you can sign up for direct deposit or PayPal with them?