Quick follow up to this... I was talking to a friend at work about the list.txt file, and he agreed that was probably a UAC issue, but the drivers left him baffled.
On a hunch (because of the MIDI device limitation), I checked hidden devices and was floored at how many duplicate devices this machine had (50+ in total across all areas). I had to painstakingly delete them one by one (all that were greyed out) and everything seems snappier now. All-in-all, some things had been duplicated 4 times over.
Since this bothered me, I checked my Win10 machine at work and that had about 25 duplicates too.
They will return as things are connected, but the duplicates in "shadow copies" and "storage volumes" I found rather odd on both machines.
In case anyone is interested,
this link is a good site to check for unused drivers. In addition to the above, the ones in "Human Interface Devices" and "USB controllers" are the ones to check. Shadowed items are installed devices not in use.