190$ is a good price, you can always sell it again without loosing money. The lens is a classic, I should have bought one when I had the chance to, but it's performance isn't that great a rokinon is probably better if you are looking for quality.
The worst thing that could happen is an email from panasonic to please remove the instructions and I doubt they would do it. They will remove the app and change it, sharing the old app would be the only illegal thing.
If you haven't modified any software, just using software as it is, it's perfectly legal to say how you did it. It's also smart to not update and backup the app because it will be gone soon.
Try to focus without the anamorphic lens, then screw on the kowa without changing focus, then focus the kowa. If you get it perfectly sharp you will know it's you. Also remember that there is a minimum focus distance (1meter?) and that F4 is way to low for that kind of light (but there is something wrong with focus for shure)