P1397 means, CAMSHAFT POSITION SENSOR B CIRCUIT, BANK 1. Camshaft Sensor B is the Exhaust Cam sensor, I'm pretty sure. Sensor A is on the intake cam, sensor B should be on the exhaust cam. P1519 is the A CAMSHAFT POSITION ACTUATOR, BANK 1.
Have you played with the VANOS? The reason I ask is because you have issues with both of your cam postion sensors. You say VANOS codes popped up, but the code trarnslators that I have don't show any VANOS troubles, you have issues with sensors.
I still believe your misfires are related to the position sensors, and you can ignore them for now. That is, when the position sensors get dialed in, the misfires will go away. Don't waste any diagnostic effort on stuff like leak-down tests because these tests are looking for weak cylinders -- rings, valves, that kind of stuff -- but you have timing issues that arise from faulty sensors.