About editing the master branch, I don’t think it should be read-only. I think the git flow of commits is now available and I’m loving it. New features should use specific topic branches, but hotfixes can be made directly to master for simplicity and to quickly make the fix available in production.
Make some branches always read-only or read-only by default would be a limitation that would not be in the best interest of all. I just think that the should test some different approaches to how the editor knows when to change branches and things like that.