About SketchUp and Mac shortcuts, it depends on the nature of the window. The model info is really a regular window, and although you can open it with Command-Shift-i, that shortcut is just for opening it. You close it with Command-w. Fonts is a regular Mac palette, and does open and close with Command-t. Entity Info is different, it’s a collapsable palette. Command-i will open it expanded the first time, then after that it toggles with the palette is expanded or not.
So, though it’s a bit strange and apparently inconsistent, it’s because the windows are different types.