It's been a while since I last tried a repair installation (it wasn't successful), but I've made a lot of changes to the system since then. I do have installation media available and know how to do this. I'll probably try some other things I've found in researching this before I resort to doing a repair installation. I'll update this thread as I work forward with this.
The VSS problem is not critical since my backups are working, and I'm able to access shadow copies using ShadowExplorer (if I ever have a need to do it...). My biggest issue is not being able to run sfc /scannow from even a command prompt via the installation CD, let alone safe and normal modes. Some of the other issues I'm trying to clear up all point back to being able to run sfc. One issue is getting Windows media player to launch, but I do have other more important things needing repair (I can't recall them right now, because I'm in a rush right now - I need to keep a written list!).
Since starting down fixing things on my machine, I've accomplished:
1.) Completely repairing damaged sxs;
2.) Restored the capability to boot into safe mode (details in another forum's thread).
Thanks for your help so far, and if you run across anything, please let me know. As I said, I'll update this thread as I move forward.