You'll have to replace the oil pick up and oil pan if you're putting a transverse engine into the longitudinal mounted Passat. You'll have to figure out the correct parts to prevent oil starvation when accellerating or cornering.
You don't say which way the donor car intake mainfold faces, nor anything about the turbo and exhaust manifolds. Take that into consideration for mounting the donor engine. That right side is pretty tightly packed with the engine mount, turbo, turbo support, exhaust and starter all packed in there.
Does the flywheel accommodate a starter in that position? From mention of that it reads like you're going to swap in a manual transmission too. If not, then you'll have to mount the drive plate parts from the BHW to the donor engine and make sure the crank will mate properly to the torque converter.
There are large number of things that need to be properly planned for such a project. It is not a short answer. However, the injector harness connector should not be a problem.
The cost of doing all of this, plus time, exceeds that of replacing the BSM before a failure.