When you add a new folder you should be able to "add to all users" instead of having to open every one up one at a time and check the box. Really a hassle if you share with a larger group of people.
Maybe not all users, but being able to select who to share with at the time of library creation is a good idea. You get my vote.
I like that more!
How about having a separate tab in the library edit window that shows all users the library is currently being shared to (with ability to add/remove)? This would allow for quicker sharing post library creation as well.
Early 2021 clean-up: duplicate