The women giving birth aren't really the mothers though are they. They are merely renting their wombs. The egg and sperm provided by the couple..... that way she gets to keep her body small and the rest ok for him...
Yes they are. In this country the mother carrying the baby is the legal mother I think, not the person the DNA came from.
The mother baby bond at birth is based on time together, not DNA. The baby's whole existence to that point will be inside its mother's womb. S/he will know their mother's voice, heartbeat, smell.
Please don't let the fact there's a financial transaction here make you think about babies and women as objects to be owned or rented out. Both the baby and the mother are human beings and this should matter.
The biological mother and father should not be afforded more power here because they paid. This is hugely immoral IMO.