Ok, super late reply
for every video where there was the UB setup into combo there was a mixup so you couldn't really use any... unfortunately I'll just give this win to Shiro
HOWEVER!!!!!!
The MAIN reasons why these Carl players were not winning was because of their lack of crossups/mixups, which I just noticed while looking at vids again :3 which hurts my eyes since Carl should be abusing vivace/anything dumbT
Also, I agree with the lack of terreza being dumb since that move is what actually gets the most wins. The other reasons you posted were phooey and you don't really need to optimize combos with Carl in CP because of 46D's incredible properties
http://www.youtube.com/watch?v=Y31a_lmfXdA&feature=youtu.be&t=2m52s <----- I didn't even notice the damage potential until I had to look at the videos AGAIN but more importantly look at the position it puts your opponent. If used properly it sets them up for another crossup/combo attempt, which few players aren't focusing their attention on
So this all means that Carl doesn't need the UB setup alone to win, but most Carl players were losing because of their lack of mixup attemps, period.