I've been using IceWM for about 10 years now. And I maximize and minimize a lot and, guess what? I've been doing it with the keyboard for years too. People who watches me managing my windows can't follow my speed of action and are frequently amazed.
The trick is simple: alt+space activates the context menu of the current window (just as if you clicked right button on the title bar). The, you have the three most common options just a centimeter from your finger: X to maximize, N to minimize, C to close. Both X and C can be typed with the same hand that has pressed alt+space, so it's quicker than, say, alt+F4. By the way, this three options work exactly the same under Windows, so it's a pretty good habit.
If I need to move a window around, I will never click on the title bar: I will type alt+space+m in 20 miliseconds and then I can move the window just moving the mouse from where it is, without the need to go to the title bar. This also works on Windows.
If I want to send a window to another virtual desktop, it's pretty easy: alt+space+t (for move To), and then the number of the desktop. Want to make a window on top of all the others? alt+window+y (for laYer) and then A (for Above dock) or N for Norma, or maybe B for Below... and all that just with one hand at the speed of light.
Long live to IceWM!