Those are all things I do miss from the Amiga, but here are the things I most miss:
The focus paradigm. Windows and Mac use 'click to focus, focus raises window to top'.
Xmouse is 'hover mouse over window to focus, click raises'.
Amiga did 'click focuses but does not raise window'. It combines the best of both - you can focus a window that's behind another one, and you don't have to worry about tapping the mouse (or trackpad!) and changing the focus because the pointer moved. You could also double-click to raise the window, and windows had a depth widget that would raise it to the front or push it to the back of the stack.
The other thing I miss are DataTypes. The easiest way to explain DataTypes is 'Video codecs, but for everything.' Install a PNG DataType and any program that works with images suddenly understands PNGs. There are text format DataTypes, sound format, video format, etc.