The 2 Canon cameras that do well in low light do not have HD video, the Canon s90 and G11. If you want a short shutter lag, term used for the time it takes for the camera to take the shot after clicking the shutter button, then you'll need to look away from the super-zoom cameras.

Also, all video is not created equal. There are non-HD cameras out there that take better video than HD video cameras. You have to read the reviews to find out how well the camera did in video.

All in all, you're going to have to prioritize your list and maybe give up one of the things you wanted.