I have the DVD box set. So I guess the kiss is only temporary.
Going back and watching those scenes in
Superman IV, I realized it wasn't so clear-cut as a I remembered it being. The whole thing is really open to viewer interpretation. My interpretation of Lois going along with the gag works, but so would an interpretation that Superman is using Lois, somehow making her constantly remember and forget and remember again. Or maybe as Lois' love grows, so does her inner knowledge of Superman's dual-identity. There are probably other interpretations that would work.
And what about Lana and the ring?
No idea.