On the second picture showing the innards of the power supply, it looks like on the top left the bare screw delivers the power (you can see there's a PCB tracing coming off the cap to it) and the black screws are either for mounting or chassis return.
And looking at the heat sink, some of the posts appear to make contact with the metal rings around the through holes where they would line up, indicating the heat sink's use as a ground plane.
I have to admit, this is creative engineering.
The Silverstone Raven RVZ01 is about as close to the chassis as you can get.
I'm concerned about the power supply and CPU shroud having what looks like proprietary, if replaceable, parts.
Am I the only one who's a little miffed that the size of the Xbox One could've been made smaller if they didn't have that relatively large open space there?
The Cortex-M0 line is actually meant to compete with 8-bit and 16-bit MCUs, though they are slightly pricier still. It still depends on what's needed (and you need at least 13 I/O lines).
As other said, it's to cover their butts when people use lower quality PSUs, among other things (like a fully loaded system). In reality, gaming computers use a lot less power than people think. I have a system with a Core i5-2500, 4GBx2 RAM, a "regular" motherboard, a GeForce GTX 670, a sound card, a hard drive, and an SSD. Running say Crysis, my Kill-A-Watt reported it was drawing about 200W-230W.
I took my measurements and ran it against eXtreme Outer Vision's PSU calculator at 100% load and found that running Crysis didn't even draw 60% of the total power load (and 60% is the lowest their calculator goes)... if that means anything.
HDMI doesn't support VGA signals, so you're going to have to convert it.