It requires replacing the head gasket.
It is a good idea, most the time you blow a head gasket the head will be warped.
Yes.
Average cost to replace a head gasket is $1000
Parts are vey cheap unless the head needs replacing. Labor is very expensive due to the time required to perform this major repair.
Your cylinder head gasket needs replacing.
shop vac
It could, if the old gasket had failed.
Depends on where you live. This is a major repair and is expensive. I would guess from $300 at a minimum, if nothing needs replacing except the gasket. If the head is cracked or wrapped, then it will cost more.
no
how long does it take
The head gasket itself isn't actually expensive. The labour of taking the head off and back on is the expensive. For example when I did my car it was £60 for the gasket and if I was to go to a garage they would of charged £200 labour.