Yes payment is sent after 3 weeks once the pay period of a week ended and u made over $100, this is happening all the time not only for the first payment.
Good traffic?! Is not for everyone sad lol, now a days Streamate is a' gambling' site, u may get good paying traffic or sit in a dead room for hrs on end.
Summer is also slow for camming on SM, they run contests and bonus weeks all the time and i know for sure traffic is directed to the popular rooms that make alot of money during these events so yeah, it's like fishing, waiting for them to bite... no easy money on SM, not for everyone