and the chances are 99% that it'll never happen but i thought i'd run it past you guys see what you think...
how about a box, that plugged into the mouse/joystick/parallel ports that connected wirelessly to another box that had 4 joystick and 2 mice ports on it?
joy1 and joy2 are auto switched with mouse1 and mouse2 depending on what is being operated. like the old robo shifters. joy3 and joy4 are dumped through to the parallel port a-la 4 player adapter stylee.
no need to run a bluetooth stack on the amiga, as far as it's concerned, it is directly connected. the sender/receivers deal with that. kinda like a wireless extension cord.
extensions to this idea include a serial port connection, so that another "master" box on another amiga could connect to it in a virtual null modem. Lotus2 over wireless

. maybe a virtual parnet link. though going this far may require some config software on the amiga side to tell the two "master" boxes how to interact with each other, and how to assign the slave controller boxes.
maybe even have an audio connection and a small audio reciever that sits down the back of your TV... but if you have a wired video hookup, running audio aswell isn't going to be too bigger deal...
other idea is to have one receiver box per joystick/mouse, but that then starts cranking up the bill of materials....
basic idea being that the miggy is in another room, AV rack, tucked out the way somewhere, and you need your controllers in the living room
thoughts? comments? suggestions? :-)
--edit--
keyboard port?