Hello Andy No, the USC is not required. It is now referred to as the LifeCycle Controller or LCC. Some also call it the LCE for LifeCycle Controller Enhanced. The LCC is an operating system that runs on the iDRAC. The two are interdependent, but all functionality that the LCC provides to the iDRAC is not required for functionality. The old DRACs are just remote access controllers. The iDRACs are also baseboard management controllers, so the old DRACs are not required for functionality. The new iDRACs are kind of required. If the iDRAC is not functional then the systems power and performance will not be properly managed. It will run at lower voltages and higher fan speeds to compensate. This will keep the system from running at optimal performance. While the LCC is not required it sounds like you are having issues with the iDRAC as well, and that is required for maximum system performance. I would recommend resolving all issues with the iDRAC. In the process of fixing the iDRAC you will likely resolve the issue with the LCC. Thanks
One of my clients has a T710 server which is working OK as a server but there are problems with the USC and this feature is not usable unless I fix it. Some time & effort has already been spent on this but before going any further, I just wanted to confirm whether USC is vital to the server's normal operation - as far as I can see, it's a useful feature that a lot of other servers lack. Obviously the client won't want to spend money on getting a non-essential feature fixed. The server runs FreeBSD so the usual Dell Linux & Windows tools are not usable - iDRAC6 Enteprise is working normally although stuck at version 1.11 as attempts to update it via the iDRAC web interface fail. Andy 
Dell T710 - is a working USC essential?