>"My main concern with the hx9v is the flash placement."

I wouldn't worry about the flash too much. Unless you're in the first couple of rows, the flash won't reach the performers. And even then, it will wash out the stage lights.

>"My only real concern thus far with the hx200v is the camera size. The quality and zoom seem fantastic, but a friend of mine mentioned that venues may take this camera as a "professional" one and not allow it in."

Your friend raises a valid concern. Also, I wouldn't put too much emphasis on the zoom as the more you zoom, the darker/slower the lens gets.

>"Should I look at a different camera altogether?"

IMO, yes, because the small sensors in both of your choices won't do well in low light. Although, the slightly faster lens and higher ISO capability of the HX200V would make it my choice if I was forced to choose one or the other. (Notwithstanding the above concern about its size.)

Personally, the only fixed lens camera I would consider for concert photography at the moment is the Canon G1 X because it has a much larger sensor that will do much better in low light. The vari-angle LCD also makes it much easier to shoot over the heads/arms/hands of the people in front of you, especially in portrait orientation (to better frame a singer or guitarist). It's also a little smaller than the HX200V, so less likely to get flagged by security. The main disadvantage is that it costs roughly twice as much as the HX200V.

Mark