representative payee income qual?

My son currently gets disability benefits and his mother is the Representative payee. He has been living with me, but she is still collecting the benefits and not using it for him. I am not looking to open pandoras box and open a misuse of funds case and am just looking to become the new representative payee, so I know the money will go to him. I have a telephone call with them shortly for approval to become the RP. My question is, do they need MY income and does that play any factor in him continuing to get the benefits? What is the approval process like? I would love for him to manage his own money and have no representative payee, but the last visit deemed he needed one and has been that way since he started getting benefits. Can he be on the phone with me during the application and switch me to the RP at the same time pending the approval or does he need to call and set up an appointment as well? Can he change the RP online after approved? Any help would be appreciated.