a) This is an installment loan, NOT a payday loan.
b) CNG is legal in Missouri and every other state that they lend in.
c) Put a debit block on your account and then work with them as they directed.
The thing to remember is that while you may hear the occassional bad story about a legal lender, they will abide by the laws of the state in which they lend unlike illegal, online lenders.