That command line seems OK. The only thing I can think of is that your 9.0.4 image is not new enough for Qemu. Find one with rom version 5.6 or above. You can search for e.g. 9.0.4 for the Cube.
Coincidentally, I'm also just now trying to install a version of Rhapsody.
Apparently only Mac OS X Server 1.2v3 is able to run under Qemu.
I could boot the image exactly once, but I restarted because during install I got an error that the chosen disk is not bootable (or similar).
After this, every time I restart Qemu with that config the boot process crashes, even with a fresh copy of the image! I don't understand that, if somebody would be so kind and explain how that's possible?