You still can’t compliment your date even though she’s your kallah because she’s still an ervah to you.
1) Shok b’isha erva
2) Kol b”isha erva
2) Sei’ar b’ish erva
This is the first time I have ever heard my life that being a kallah is an erva.
I haven’t read this book, so I cannot intelligently comment on it, but having said that, anyone can write a book about anything, including a rabbi. Could someone please educate me as to the makor for a kallah being erva(not just the totally correct idea that a chosson and kallah have to be extra careful not to get caught up in hormones and emotions, which could lead them to be nichshal, but an actual makor that says the kallah is erva).