Hi
Welcome back!
Mac Mini is the greates MorphOS machine ever I have to say. Unfortunatelly you've got the 32MB VRAM version but it shouldn't be any problem at all with correct system settings.
You will be able to run UAE to play old Amiga games with no hassle at all. There is an article how to setup UAE with Ambient (MorphOS Workbench).
I would recommend to go to morphos.net and download MorphOS iso, it works for 30 minutes and after that time it slowes down (without registering).
At the moment WIFI is not supported at all, but it might change in the future.