Hey, I just was going through everything and think I've learned something!
I did the multimeter check again and I was wrong before. The pin layout is the same as the MightyBoard Rev G diagram I linked to earlier, except NOT upside down (though the board still is upside down, compared to mine). So, maybe that's the only difference between our boards.
I rewired to match the Felix 3.0 video (matching on pin names, not left to right order) and ended with (left to right, from the view of my board linked earlier) 1A - green, 1B - black, 2A - blue, 2B - red. That didn't make any difference in how the motor ran before (green and black reversed).
However, I decided that maybe it was moving, but just too slowly to see. Sure enough! Try the connections I mention and put a mark on your white gear. Mine moves 1 tooth per 30ish seconds. Very slowly, but it is moving.
So, I'm now wondering if maybe that's just how slow it's supposed to move. Or maybe something needs to change in software. I'll keep playing. Well, actually, I just got the most of the parts for my first quadcopter build, so I may be distracted for the rest of the evening But I'll fiddle with software later and connect a syringe with something and see how it goes. Hopefully I'll get it all working and I'll write up a more detailed guide with photos, but let me know if you want to see anything else on mine or if you solve it all