Got the Alpina TCU reflash (the older, more-liked version) working this morning.
First attempt at flashing bricked the car with the gear error. Got 100% through the coding, but never gave me the "coding complete" pop-up at the end, but rather, asked if I wanted to start coding (again). I figured it didn't take, and sure enough, it didn't.
I tried flashing the trans back to the stock software, which worked perfectly fine, and coding ended like it should have. Car was drivable again, thank god.
Knowing I could always recover from a lock-out/gear error, I figured I'd give it another go. Sure enough, it worked the second time (with no other software/daten changes/updates. I guess it was a fluke error the first time?
Paddles didn't work right away, but after reading the EGS module in NCS per the below DIY, they functioned again.
http://www.e90post.com/forums/showthread.php?t=874072
Went from not being able to get software running 3 days ago, to having everything done this morning.