We can put forward one more argument in favour of Black hole being cold. We know the end of Sun like stars into a White dwarf. This is a smaller, denser and cooler celestial body. If it becomes even smaller than that, like in a Neutron Star it would naturally become more cooler! If it gets into a Black hole form it becomes even smaller and more cooler?
Black hole keeps eating up few stars every year. You may think what happens to the energy? the answer is - it gets converted to mass. You have heard of mass getting converted to energy in an ordinary star, but never the other way round. Here you are hearing it for the first time. So I can understand it is difficult to digest it. But don`t you think it can happen?
One more thing. You have said temperature is directly connected to the motion of the particles. Yes you are absolutely right. In black hole you know the compactness of matter. Where is the space left for movements?
You may read more of my views on black hole and its surrounding on http://geocities.com/indumamtora
Your comments are welcome!