Unless you can find a SX- expansion with IDE for your CD32, you won't be hooking up an IDE drive to it, and without the proprietary CD drive connected you won't be able to load anything. You are really better off keeping it in its original case, maybe sticking it under the TV and hooking it up via S-Video, burn some game compilations onto disc and play them from the couch. You can easily put the compilations together yourself with this Windows program, which works in Wine too: http://mygurumeditation.wordpress.com/cd32-toolkit-assistant-help/
You can use the CD32 to send ADFs to the A500, but you will have to wire up a serial port to the AUX port. You can make a splitter that has both the serial and keyboard port and use them both at the same time too. Check this out: http://aminet.net/package/docs/hard/CD32-Amiga11
An SX-1, SX-32 or the incredibly rare ProModule are the best options - no need to rehouse anything, and they give your CD32 a full complement of Amiga ports, some Fast RAM, IDE interface, and floppy interface. These are great systems for games and light productivity!
