This thread is huge so I will go ahead and ask these two questions:
1. Can one rig use two different miners at the same time? For example if I have mixed nVidia and AMD cards on one rig, I'd like to set ccminer to mine lets say ravencoin and the AMD cards to mine ETH. Is this possible?
2. I suppose the rigs would need to have windows installed on them. Is it possible to boot them from USB without the need of a hard drive?
1. Yes, use the -d / -di directives in command line parameters in your case...other software can be configured similarly if they support device assignment
2. You can use linux too, but for Managed Profit Miners, then you'd have to use Windows I believe using Remote AM Service. Unless you use the premium version and implement your own rules and manually profit/profile/template/pool switch via API. as for Windows on USB, never tried to use them to mine, some others might be able to shed some light.