x = Mac OS X on startup
command-r = Lion Recovery
Apple has an HFS driver that will panic or worse if it detects an Apple array but MacDrive will mount such an array
Try running Memtest, even though you have ECC
8-cores came out in 2007 so doesn't tell me anything as to which model or even the GTX in case that helps.
Obviously you need Windows 7 Pro 64-bit.
If you burned a Windows ISO that can be an issue. Retail or System builder then no.
Could also remove all other drives for now.
Lion Boot Camp Assistant downloads the drivers, and 4.0.0 set were bad so you might want to make sure you clone+update Lion to 10.7.3 and download current drivers.
And yes most things do work fine but not system power management and control w/o the Apple drivers.