Are of the above are potential issues, but it won't necessarily show all the signs. Waterfall noises behind the dash is from air in the cooling system, white smoke is from coolant in the combustion chamber, overflow bubbling over is from over pressurizing the cooling system due to compression leaking from the cylinder in to the cooling system (in the case of a blown head gasket). Another common symptom is a miss especially on cold start if there's enough coolant making it in to the cylinder. It all depends on how bad it's blown and where.