(EDIT): I had downloaded deviceclean by mistake. Attached are the results from -t. Two questions:
1. When a device is removed, is it simply automatically reinstalled when seen by the OS next time such as the an external drive, USB's, etc?
2. I think the only device that would be a catastrophe for this tool to remove would be one of the two internal drives. Is the tool just for 'plugged' in devices? Is there any removal (type) that if done would be characterized as a really, really stupid move?
In Post #1 you wondered if the USB problem might be related to the SR point question, and IMO the answer to that was "maybe" though Windows should NOT have ever allowed you to set-up SR points on a removeable drive. In any case, I learned a long time ago that one should "fix known problems, then if you do that sometimes other ones go away". Hence the USB thing.
I have used DriveCleanup for years and have never had a problem with it as I said before. Further I have never seen as long a list of items to remove as yours. So it looks ugly to me because the entries represent a lot of junk for the OS to wade through. What DC does AFAIK is it starts with: what is Connected? Ignore that. Then it proceeds with: what is Not Connected and what regvalues are associated with the unconnected items? That's your 53.
To your questions:
1. Yes, if you remove a device and uninstall its driver, when you re-insert the device it will re-install the driver
2. The tool does only affect non-present, not-currently-plugged-in USB devices. For grins plug something(s) in, run drivecleanup -t again, and observe those items are missing from the "stuff to remove" list.
As for potential problems/stupid moves I would ask: Do you know about Windows Device Manager (right-click computer on desktop, select Manage, then Device Manager)? If you were to eg. use Device Manager to uninstall an internal drive, you could reboot, or just select Action/Scan for hardware changes and the drive would re-install itself. So I don't know how the USB tool, even if it somehow screwed-up, could break your PC, but neither can I promise you it won't.
So if you're not comfortable with doing it, or if the problem is so minor you don't care about it, then don't do it.