This sounds like a very cool project.
There are two features that I would submit for future, post 1.0 release. I realize that 1.0 hasn't been released yet, but I know I like to think about where I am going at least one version ahead when I write software. So, my suggestions are:
1) Support for the CatWeasal. This would pretty much make the system into a real Amiga, as even real Amiga floppies would work.
2) A way to reconfigure the system as different Amiga models on boot up. I don't like the idea of a menu at the beginning, as that would spoil the fantasy. It would also force user intervention for boot up. That would be a bad thing. Some non-intrusive bootup options could be:
a) Look on a SD card for a config file. This would allow model switching by just pulling out one SD card and inserting another. SD is cheap, and even throw away 8 meg SD cards would be plenty big for holding the Kickstart and config file. If no SD is found, boot to the default configuration on the hard drive.
b) Allow F-keys during the 15 second boot, to change the configuration. This could work similar to the way you can press an F-Key to change boot up drive on most BIOSes. This would be cleaner than a menu, but it would still require user intervention during the boot.
c) Have an Amiga application that will change the config so that on next reboot, the system is a different model. This would require that the application be available to all installations, so it could be quite a headache.
Actually as I type this, a third feature request comes to mind for even later in the development cycle. How about an Amiga application that could change the ADF that is loaded. It could work much like Alchohol 120%, or DeamoneTools works for CDs.