DF (non Bio dad) and me swapping roles? how do centrelink payments work?

OK so say DF and I decide I go back to work and he stay home with the girls (this is all theoretically)

ATM on his wage i am entitled to a tiny amount of Parenting payment partnered and full FTB.

now Im guessing that centrelink wouldn't let him apply for parenting payment partnered if i was on a similar pay that he is correct?
so how does the work? i mean we live together they take away a single parent income saying they have someone providing for them but he then can not claim the payment if he decides to be the stay at home care giver?

and FTB? will that stay in my name and if i earn the same will it say the same? because its a family income assessed?

hope that makes sense...

FTB is best kept in your name - if you change it over, it's messy
no reason at all that he can't have PPP - he is the step parent, you are in a marriage like relationship, he can claim it as their primary carer.