Looks good, although I have some comments.
Are we really saying that developers can choose whatever license they want for standalone projects? Surely if the code is being funded by LSST then the choice of license must be an LSST decision not a developer decision. I would assume that if you are not using GPLv3 then you must at least talk to your T/CAM. I agree that sometimes Apache or MIT are a more obvious choice but it's not up to the developer completely.
For "Applying a license to a repository" if you aren't using a template (because you are standalone) then are we okay with adding one from the list when you create a repository using GitHub UI? It is a bit odd that GitHub does not list creative commons on that menu.
The "Use your institution's email with Git" directive has not made everyone happy but I'm not sure what we can do about it since I think that is is confusing for a senior UW person to use lsst.org email in commits since lsst.org implies AURA.
We should mention that it is possible to set up per-directory tree emails so that work commits and personal project commits can use different emails via IncludeIf (see https://blog.github.com/2017-05-10-git-2-13-has-been-released/#conditional-configuration).
Typo: Background: "does not current exist".