Megabit wrote:

"Frankly, I'd like to also move all the %Userprofile% contents from C: to D: - but am a little hesitant to do that for fear something might go wrong, and create havoc on my otherwise clean and stable system.

No, I haven't done so and here is why I wouldn't: cutting the fat on the system drive is always good and as others have pointed out, there are all kinds of things that can be knocked over to another drive. But starting to noodle with how the OS interacts with programs and so on is asking for trouble. There are so many tiny files such as .dll and registry key interactions that depend on specific chains or order of "ignition."

In other words, it's great to clean house, renovate, go minimalistic, but I'm not going to start digging into the walls to try to trim back the beams and 2x4 holding up the house; I could also end up accidentally cutting into some of the house's electrical wiring and plumbing :)