I tried what you say, you can disable unsigned driver enforcement, but as soon as you reboot it wont load the unsigned driver, i could be wrong though i have not tried it for a while.
Also i dont have a problem with x64 particularly, its just that it has been out for ages now, and there is still hardly any progs/games that use it nativley, show me a list of native x64 apps/games i bet its not very big.
The unsigned driver is loaded after a reboot, unsigned driver enforcement only prevents the driver from being installed, once it is installed, it will load just fine from then on.
And it doesn't matter if there aren't that many native x64 programs, the point is that having an x64 OS will allow you to use the programs that are native x64, while x86 will not. Using x86 limits you, even if it is only a minor limitation right now, it is still a limitation. And purposefully limitting yourself for no good reason doesn't make any sense. Besides that, while the programs themselves can only address 2GB of RAM(yes, x86 programs can only address 2GB of RAM, not 4), what x64 allows is for more programs to be open at the same time, thanks to the larger amount of addressable system memory.