The two built-in lenses are self-developed and currently not compatible with other lenses. 

No, no focal length or aperture change. Works absolutely like the Canon original that I use.  

I actually have not received this adapter yet. It's shipping from China. Don't think that was disclosed in the ad. However, I do not believe this is for the Pentax Q body rather for digital and film cameras that take the Pentax K mount in its many variations. So I'm expecting to be able to mount my Leica M mount lenses on my digital and film Pentax K mount cameras, no autofocus or relay of exposure information, only to be used with manual focus and exposure. 

An adapter does NOT change the focal length regardless of what is mentioned in the 1st answer. The adapter *can* be used on a camera with a smaller sensor which would change the filed of view of a particular focal length. 

A RF lens like a Leica-M lens will NOT focus to infinity on a SLR body like the Nikon. The Leica lens will only focus to a few inches, like a macro lens.