The nightly release is tagged with the date e.g. as: 1.8.0.dev20201109

You might see more issues, as the nightly will be rebuild every day from the current master branch. That being said, I don’t have the feeling that the nightly is terribly unstable.
Yes
You can use the install command from the website 71 (same as for the stable release) and specify which cudatoolkit you would like to use.