can exhaust manifold leak cause you to burn oil
engine oil leak
they leak oil from the oil pump on the front of the engine
If the casing is spilt a filter will leak an incorrectly installed filter will also leak.
It will continue to leak oil and if you do not add oil regularly it will eventually cause engine damage.
a leak or burning it
An oil leak is always going to be out of the engine as the engine contains oil and the car does not. I think you are saying you are loosing oil with no apparent leak. If that is the case the engine is burning oil and that is why you see no leaks.
Yes.
Yes.
A major leak.
yes
Anything else that the oil goes to.