I believe that babies can sense stress. Are you stressed? If so, she is reflecting it.
Why not rock her? It's a special bedtime ritual. I don't consider it spoiling.
If she's used to a bedtime ritual and now you are changing it, that is why she is crying. She can't say "mommy why are things differnt?"
I used to talk to my daughter all the time. I found that when I told her of our daily plans, things went smoothly. When I did not, she would be fussy and a real pain. I started experimenting with this when she was a week old.
When she was old enough to talk, she'd ask each morning, what is going on today. It helped her feel secure if she knew the plans. It did not matter what the plans were. Some days I would say, I'll pick you up from school but I don't know what we'll do and that was alright too. She just wanted to be in the loop.
As a mother of a grown child, rock the kid! Before you know it, she won't want it anymore. They grow up so damn quick.
Your job right now is to be a loving mommy. I don't know who told you that you were spoiling her. You are loving her in a way she can understand.
If your husband is jealous (lacks your attention!) then tell him that after you rock her to sleep, you'll come give him some "special time too". (SEX!)
Sometimes mommies are too focused on the kids and forget that daddy needs loving and special time too!
It's almost Valentine's Day so plan something "special" for the guy that made you a mommy!