Figured out my problem.
As assumed it was a filter pointing at a Visual Studio Virtual Interface.. but it was all my fault.
I was using a filter to snoop on Third Party Video Capture applications to discover their Filter Graphs.
When I removed the user interface application for this filter it didn't remove the filter and it hung around overriding the device driver filter, directing it to nowhere.
The reason GraphEdit worked, was it did not trust the Merits of the filer store and hooked up its trailer hitch directly to the device driver.
Once I removed the virtual interface filter, everything started working again.. except for one small thing.
I'm running Windows 7 x64 edition for this test.
The device driver installer [ Pinnacle_Video_Driver_64bit.exe ] as written for Windows Vista and has a bug, and Windows 7 reports it is unsigned.. which part I do not know. Its an InstallShield application wrapping a Windows MSI installer, wrapping a set of device drivers for Bender, DVC100, and Marvin Cr, Lite and Classic with the Marvin Bus.. all to go over USB.
If you watch carefully when installing it.. it actually bombs and rollsback its install at the very end.. no device drivers are actually installed when trying to use [ Pinnacle_Video_Driver_64bit.exe ]. Instead.. Windows Update jumps into the middle of things and pulls a device driver checked into Microsoft HQ for Marvin (the actual name of the 500, 700, 510, 710 family).
So in reality.. at least for Windows 7 x64, you don't need [any] device drivers.. as long as Microsoft is still serving them.
However
This is a Big BIG PROBLEM come January 2020 when Microsoft shuts off support for Windows 7. Those device drivers may stop being served and things could stop working.
I'm studying, trying to trace down why or which part of the compound device driver that is double wrapped in [ Pinnacle_Video_Driver_64bit.exe ] that is failing and causing the rollback.
It might be that some part is unsigned and the x64 version of Windows is hacking up a hairball.. but I suspect its some incompatibility in the installer or driver that was intended for Vista.. they made it this complicated because this is a [Multi-Family] device driver installer.. Bender, DVC100, ect... somewhere it has to run a check to decide which set of drivers to install.. any one of those could be the problem.
The alternative (to be on the safe side) is to backup or export the installed device drivers, so you could reinstall it independent of Microsoft.. if they really do pull the driver support for Windows 7 x64 come January 2020.
The 500, 700, 510, 710 do excellent under
VirtualDub 1.9.11 and probably more.. Preview always has to be set.. Audio levels can be set but recording with Audio playback on de-syncs the audio and video.. so remember to shut the playback off when actually capturing.. audio will be captured.. its the audio playback that skews the synchronization while capturing. While you watch it your watching a "lossy" realtime view which you can't tell is dropping audio samples or video frames to stay in sync.. it doesn't matter.. your brain fills in the gaps.. but video capture files can't lie to you.. when you watch those they will show sync errors you can't correct in your brain.
For those "playing at home"
The command to get [ Pinnacle_Video_Driver_64bit.exe ] to explode its driver set is:
MSIEXEC.EXE /a "\Pinnacle_Video_Driver_64bit.exe"
That will open a GUI window and ask "Where do you want the Administrative Network Install to go?"
Point it at a directory you've already created for it and it will dump everything in there.
The subsequent .msi file is the actual Microsoft MSI installer, the directories contain the device drivers.
The MSI installer is doing double time running a script to decide which family is the topic of this installation and directs the Pnp device driver installer to pull device drivers in the order they will be installed from the different directories.
The Marvin "bus" device driver is a prerequisite it layers on top of the system USB and USB host device drivers already installed.
The Marvin "av" device driver handles the actual physical device "family" 500, 700, 510, 710
The "Bender and DVC100" are physical PCI cards I think which were a different product line and had nothing to do with USB.
Its kind of hopeful that if Microsoft is serving the device drivers from Windows Vista/7 they will continue to do so.. but.. who knows.
I'm still intrigued by the mystery of why the [ Pinnacle_Video_Driver_64bit.exe ] is failing and rolls back.. the certs are all signed by SHA1 and that scares the pants off most security people these days.. it might be why Microsoft is blocking it.
