Today I created a new user role, Developer. (Read about user roles and capabilities here. I am using a plugin called User Role Editor to do this.) Tyll and Bob are now Developers. The site really should have only one administrator, and that is me (Kathy) for now.
Developers have more privileges than Editors but fewer than the Administrator. I don’t think you will notice the difference, but if you find you can’t do something you really really want to do, let me know and we’ll see what we can do. Among other things, Developers have no access to the user administrative screens beyond their own profile, and while they can customize the currently installed theme, they can not switch the theme or install a new one.
Other changes: My “display name” is now “Admin” instead of “Kathy”. This helps me remember how I am signed in, because I am also the Editor whose display name is 5CLIR. (That particular user is associated strictly with pages imported from the old site; I never actually sign in as that user.)
Other users: Katy is still an Editor. So is the user whose display name at the moment is Office Manager (first and last names are Mindi Winter, e-mail is 5clir@smith.edu.) So at the moment, this site has six users in all.