You can add and remove columns from the Finder’s List View windows on a Mac very easily. Just open up a Finder window (double-click a folder, or go to the Finder menu and choose New Finder Window) and then go to View/Show View Options. (My friend Dave likes the keyboard shortcut for that, ⌘-J.) There you’ll find all sorts of options, including checkboxes for showing and hiding various columns.
The changes you make in the View Options panel are only for the window you’re looking at when you make those changes, unless you check “Use as Defaults.”
Note: “Calculate all sizes” means “Calculate the size of folders instead of showing dashes next to them.” It isn’t instant but it’s worth it.