very nice set. My favourite is the first. A bit hot at the top left but what a capture.

Is there any lens you do not own ?

I have never noticed this before but it is worth noting that any zoom lens where the volume inside changes as you zoom needs to breathe somehow, otherwise you physically would not be able to zoom. With a weather resistant lens it makes sense that the most likely place is going to be at the mount end into the camera body.

Again if the body was not able to breathe you would have the same problem.

ps zoom lenses are often referred to as having focus-breathing properties, where the focal length can reduce, usually when close focussed. This is entirely separate from what you are describing and I add this just for the sake of clarity.

No 2 for me, very nice

There is certainly some smooth bokeh action here, but I am not sure the extension tube set-up works for me.

Screwdrive conversion is the best approach and will be mine if the 300 ever goes west.

I at one time owned three of the DA* lenses. 16-50; 60-250; and 300. The 16-50 was troublesome in that it needed me to manually focus a few times throughout the range, then AF throughout the range after which it behaved normally. The 60-250 and 300 both worked perfectly. I only own the 300 now and it is still going strong despite its age.

I think it was the early SDM motors that had issues. As has been said the more modern lenses use a different design.

RAW files contain all the data captured including colour. It is the processing, either in-camera or in software that will create the b+w image.

2nd is my choice too. Lovely

Love the second image in your first post. A classic b+w image.