We also have check-cashing businesses as customers, and we looked very carefully at both the up side and down side before deciding to keep the relationships. Honest check-cashing businesses do perform a service by assisting those who cannot, for whatever reason, open a bank account. They also contribute a huge amount in fee income to the bank's bottom line due to returned deposited items. You just need to be sure they are keeping compensating balances to cover their returned items, and monitor the activity more closely than you would other accounts. And yes, I do think that you should ask to see their FinCEN registration and their AML policy. In addition, check with your State department of licensing and resigtration to be sure they are licensed to do business in your state. I think that if you perform your due diligence, you should be fine.
Being kind is more important than being important.