Let's take a step back here: We know fastboot is fine so we know the drivers are fine, even though ADB is sketchy and I have had adb working 50% of the time.
As it stands right now, I'm in twrp and i'm successfully in adb. Seems to me I need to download another rom zip and try to get it to sd.
So here's the questions: Do I download a device specific m7 rom and is there a tutorial for adb flashing a zip to sd card.
If it doesn't work after that we could maybe try something else, but it seems to me you're right - if we can get a good rom on the sd card we can install in recovery.