White smoke is a sign of burning engine coolant due to a leaking head gasket. You did not exactly cause that. It was a problem that was about to develop on its own, and stressing the engine just hurried it along.
No engine will overheat instantly when started from cold. If you're seeing bubbles in the cooling system reservoir, that is the combustion gases leaking the other way and going into the cooling system. As proof, you'll notice the coolant is still cold; it's not boiling, and there's no steam associated with that bubbling.
Depends on the damage. It has to be torn down to see the damage.
Do not drive it till you have it repaired.
Roy
Wednesday, July 4th, 2012 AT 7:01 PM