David,
yes, I operate the Mini's via Ethernet only. I use a Netgear GS605 switch - I was told a switch handles network traffic better than a router. They don't cost much - about $40.
network setting: IPv4:I use DHCP with manual address. IP address: 192.168.0.xxx - last three is the number you assign to that Mac. This way I can conect the Minis to the internet if needed. You can also set IPv4 to Manually. I do this for my 2nd ethernet port on my main Mac, which is connected directly (no Ethernet switch) to another Mac Pro. For this I set IP to 192.168.2.xxx - I don't remember why, but it works. So afaik: use a switch and set the IPs manually, than your main Mac will find the slaves and especially when you reopen existing projects with VEP, it will know where to connect to.
I control the slaves with Apple Remote Desktop, but you can also use the built in screen sharing (activate it in Sys prefs-Sharing), which costs you nothing extra and also works great. I only had to connect a monitor for initial setup. The MIni now shows me a 1680x1050 display via Ethernet, which works beautifully for editing VEP setups.
The setup is currently very stable; offline bouncing works great. etc: it's awesome!