Actually only 1 Nic is needed. On mine, i have 12 VM's on 1 server. the EVGA mb. Works. BUT during high network traffic, (acronis imaging, or Backup exec type activities.) you can tell.
But in a test environment, only 1 nic is needed. (1 nic, console+virtual network+vmotion) easily. Iscsi, / high network activity will impact it..
2nd question- not at all.
you give the ip to the Console (IE the server). Using default install, it creates a VM network on that same NIC.
Each guest you give ip, in my case 12 of them,- They plug into the VM network, which is hooked up to the LAN. So in essense, traffice from vm to vm, is lightening fast, but from vm's on that host, to physical servers / other vm's on other ESX host's. That 1 nic handles the entire load of whatever servers need access.
Best way to get a judge of what all it is doing, is go to VEEAM and download their monitor tool, or get ESX charter. That way you can get much better idea on what kind of network/disk/cpu/mem activity that is happening on your ESX hosts.
