Probably not. They turn themselves into water using their chakra. If this was possible to do, the water prison jutsu would be useless against anyone who can use a water jutsu, and thus kakashi wouldn't have been caught in it because he could just use water dragon using the water prison's water and escape.
That would be funny. I don't see why not. But maybe because a Hozuki member is actually being used, they may have a certain level of will-power that enables them to have control whether they want to be used or not.