The software based shake reduction is for video only since video files have lower resolution than the native image of the sensor, and so there are extra pixels that can be used to estimate the shake trajectory, reduce it in software and finally store resample it to the video resolution and store in the video files.
Likely the maximum fps rate depends on the lens and perhaps the aperture as well. With the aperture mechanisms of G lenses in the longest lenses I suspect the maximum rate is a bit less than specified, while with the E lenses it should reach the nominal rate if the shutter speed is fast enough. In this article
https://photographylife.com/reviews/nikon-500mm-f4e-vr/3the author notes getting 10fps from the 500/4G vs. 11fps on the 500/4E with the D4s at f/4 to f/16, 10.5fps at f/22. I suspect the high fps is possible with short G lenses with shorter mechanical connections between the camera and the aperture blades.
On the other hand I've had some struggles with E lenses in the cold. I was shooting landscape on the sea coast and it was about -23 C to -19 C depending on the day. The sea was still open for the most part and there was a lot of "sea smoke". After a while of using the D810 and 24 PC-E I got Err and the aperture seemed to behave erratically. Some shots were wildly overexposured. I noticed in live view that as I opened up the aperture, the image went dark! It could be some communication problem with the body and lens. The camera also refused to operate in M-UP mode, reverting to S behavior. I've not seen this particular problem before and it went away after the body and lens were warm again. I'm just saying that while the E aperture control is helpful there may be still some glitches with the implementation. I've had problems in the past using the D800 and D700 locking up (with different symptoms) in similar conditions and usually I've been using a PC-E lens in those cases though I can't remember if it the lens was
always an E lens. I would have to check old files.
