I share your sorrow here. I too, am finding things to like about iTunes 11 but still feel it is incomplete. That goes for the Remote app as well. That being said, its recent update to 3.0.1 did fix rating feature from iPhones and Touches. Additionally it fixed an underlying bigger bug with the next/previous track navigation of an AirPlayed iTunes library.
My only suggestion for you is to consisely discribe the function you feel is missing to the feedback chanel. Unfortunately, there is no direct feedback chanel for this particular iOS application. I've been using the AppleTV chanel as the method of reporting.
They do listen, they just don't talk. i've come to accept that the walled garden has greenhouse in the middle that is made of oneway mirrors.
Keep digging and posting. I was glad to learn of your trick here.