Hire a contractor. There ain't much call for stomping on chickens.
The I/O limit could be on memory. Servers can have >1000 times more RAM than there is cache on a CPU chip. With enough threads and/or processor cores the cache hit rate drops, so that the memory bus is 100% busy. At that point a faster CPU gives no benefit, may as well us a low-power one.
The camera will also have to be disabled because tap-induced camera motion could be read that way.
It may also be possible to get tap position information from the microphone.
Maybe the person adding the new key didn't pay for the device. It may have been borrowed by police or black hats for spyware installation, or it may have been outright stolen. Requiring secure boot can protect the legitimate owner of the device in these cases if the owner has taken reasonable steps to prevent access without proper authentication.
Another valid reason for preventing unsanctioned OS's to run on the device is to prevent reverse engineering. This enhances (through obscurity) the security of any secondary encryption or authentication that applications on the device may use.
Secure boot is the first step in loading a trustworthy computing environment. Content and media companies will be more willing to license their content for use on secure Win8 machines because they can be sure that the content can't be easily copied.
Content not available on other devices, or only at higher prices / lower quality, is a killer app for Win8. Another one would be widely available and used IP-based voice/video communication, which Win8 will probably have (based on Skype).
Or take things logically in a different direction: Tax the sick. There's no need to theorize about obesity, smoking, age or other possible things that may indirectly influence the cost of medical care.