welcome 4th child. The mac mini is amazing.
a couple things.
I would recommend powering your usb hub. I have had sleeping issues with hubs powered off the mini. check out carnetix forums, there was a bunch of discussion.
as far as a front end, check out TatraApp, its the ORIGINAL apple frontend for a car. And tatra has it opensource, so there will always be development work on it. I tried CCar, but when it started crashing, i had nowhere to turn.
im actually about to start another thread with sad news of my install, but good luck to you.