"I was advised by my lawyer not to get wrapped around the axle about the "primary" designation. In my state at least, it has minimal legal significance."
This obviously varies greatly from state to state. In mine, from a legal standpoint, 100% of the money goes in one direction. Beyond child support, medical insurance, CP's daycare and extras, even from the angle of any government assistance, only the primary parent qualifies, even when physical custody is shared 50/50. And, from a tax standpoint, the 50/50 NCP cannot get the earned income credit, working family credit, or credits for daycare paid or school supplies.