What is the licensing scheme? I have AE3 for Classic, but would like to use AE4 with my MorphOS MacMini -- is there a concurrent license or will I purchase a new copy? As well, I am curious to know what MIDI interfaces are available for the MacMini to work with Audio Evolution.
You might want to contact Davey directly, but yes I'd imagine he'd want you to purchase a new copy. Different hardware, new software port, it would only be fair.
I don't know what USB devices he's tested on his computer. I believe the MorphOS developers helped set him up with a Powermac (so he's one up on the rest of the MorphOS community since support for that hasn't been released yet).
Still, any USB device that works on his machine ought to work on your Mac Mini.