I have these. They don't make contact with the screen, no need for concern there. I didn't like them for typing however and I removed them from all of my alphanumeric keys. I find that low friction is best for typing, and the higher friction of the wood made me type slower. The corners are also sharp so your fingertips catch on them when sliding from one key to the next.
Also, note that the upper right key used in the images is a power symbol, not an eject symbol. The eject symbol is positioned with the arrow keys before you peel them apart and apply them, and this throws off the "flow" of the grain pattern.
I still have these applied to my modifier keys, but I would not buy them again.