Love, hate… I heard it's in all novels.
Scott seemed so proud to show to Xavier all his achievements in AvX 6. He must have been disappointed by the reaction of his father figure.
Rachel Summers, herself, said in Excalibur that the Phoenix functions with emotions not with rationality.
By the way, she has been the best host of the Phoenix, always able to keep it in check. For all her traumas, her personnality is more solid, with less flaws than her father.
But then she grew up in a loving family until everything was destroyed.