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When in Library mode viewing a single image, the image looks blurry 
. When I click to zoom in, it is very very sharp 
. When I zoom back out, the sharp version is displayed for a split second at the smaller size, then it switches back to the blurry version. I have generated a 1:1 preview, which I thought would be exactly this type of control, but it is still blurry.
Any thoughts?
I think your "sharp" image is downscaled using nearest neighbor interpolation. It just shows some pixels as they are, and drops the rest. It is a very fast method and that's why Lightroom uses it to quickly show something.
The "blurry" one is downscaled with a more sophisticated method, maybe bilinear or biqubic in Photoshop language.
The nearest neighbor interpolation seems very sharp, because light points and sharp edges are not diluted by linear combinations with neighboring pixels. All the micro contrast is still there. Actually it seems even sharper than the full resolution image, because at edges many of the soft edge pixels are left off.
NN interpolation also creates jagged edges, and makes noise look worse. And it has a potential for awful moiré effects.
This sounds like a speed optimization in the software to prevent the software from overloading your resources by trying to render a large number of enormous images at all once so it downsamples each image into a much lower resolution to speed up navigation.
The 1:1 preview is only in effect when you're zoomed in. When you zoom back out, LR will be using either the "standard-sized" or thumbnail previews.
So when you say it's blurry, is that temporary? If so, then you can render the standard-sized previews to speed that up.
Otherwise, LR will generate the standard size preview and the blurry image should sharpen within a few seconds. If not, check what size you have set the standard previews to: How do I determine the best setting for the Lightroom Standard Preview Size?
In the top screenshot, you are at "Fit" size which is interpolated (say, 21.7% or some such uneven amount.) Combine this with the display resolution and LR likely has a hard time getting exact with fine detail.
When you zoom in, LR has algorithms to scale the image at say, 1:4 or 1:3 and there are also more screen pixels to render fine detail.
You might also see color differences because LR uses different profiles in Library vs Develop module.
Try adjusting the "Standard Preview Size". You can do this by going to: Edit > Catalog Settings > File Handling > Standard Preview Size. Set it to a value that is bigger than the resolution of the screen you're using. Maybe also increase the quality.
But even if you set it to a very high value like 2880px, Lightroom still will scale down every image to have the longer side at this pixel value. Now, for "Normal" Aspect Ratios (3:2, 4:3, ...) this works fair enough.
But your Screenshots show a panoramic image, where the height (and thus the overall amount of pixels) is much lower than on the other images - so it can be that these Images still will look blurry if you are looking at them in "FILL"-Mode.
Lightroom only uses the 1:1-Preview if you zoom in, or if you go to Fullscreen Preview by Pressing F.
