Leaking Manifold. Also coolant and oil.

You don't need to pull the engine to reseal the intake. It is a common problem on those engines, the most difficulty lies in the rear valve cover removal. As far as oil leaks, you have several possibilities, one of which is the oil pump drive o-ring that should be replaced when the intake is off, as that is what is needed to get the drive out. If you let the manifold leak continue, it will get worse, and may even create an intermix in the engine, where coolant leaks internal. Coolant is not a lubricant, and bearing damage will result if gone unnoticed.

That is correct, you don't need to pull the engine.