Is this a normal problem and if so how much is to fix, changing the thermostat the intake where it sits started leaking and finally split down the seam of the plastic neck below the radiator

Is the piece you're talking about #7 on this diagram? If so you need a new thermostat housing, it should be around 40$ for a new one direct from ford and under an hour to change

This housing is directly attached to the upper radiator hose, what I am talking about is where the thermostat sits and is cracked, and that housing your talking about covers the thermostat and is bolted down with two bolts. The parts guy called it the entire intake manifold..

I have the same problem what is the part called