Yes! No reason not to, really. Like all throws, its good once or twice a match. The reach on the kara-throw will mess with people fairly well. Especially those only familiar with the range of the normal grab.
Tech purple grabs and you'll be doing much better overall. Lots of free damage from that. I remember seeing a few reps of haidas throughout the set so I'm sure there was minimal lag to where purple throws are easily teched.
Hitconfirms, as Luna said. While its rare the overhead actually hits, you always have to be on your toes to capitalize.
Majority of the time, Bang stood up for your overhead before the animation was even halfway done. If your opponent is really good at reacting to overheads, sparingly throw in a command throw. Its slow as hell but most people forget that she has it. There is a huge risk in doing it but hell, we play Noel. Gotta do what you gotta do. Esp against characters who are as easily looped as Bang.