1) When I use the Warp Stabiliation the image in my normal preview monitor jumps around like crazy. (Some screen shots below - note: I'm jusing 3 videos next to each other, image should be within the grey lines).
When I export the video its fine - but for editing it would be very helpful for the image to also not jump around. Any ideas?
2) In general what are the best settings of the stabilisation effekt? (e.g. Footage of birds flying, kamera sometimes zooming and also turning)
Settings for Warp will vary, at times dramatically, depending on the amount and type of motion involved. And whether the camera is moving, the camera is (mostly) stable but something in the image is moving, or ... both.
Also, it's best used on shorter segments than long ones, as it tends to get better results. It isn't a direct replacement for in-cam stabilization unfortunately.