> Focused and unfocused windows look almost identical
I have never had a problem distinguishing.
> Expected features like tray icons, virtual desktops, alt+drag to move/resize windows, even alt+tab don't work out-of-the-box
All of the above work perfectly fine. I genuinely have no idea what you are talking about.
> Window focus seems completely broken
You'll have to be more specific here; works fine for me.
> IntelliJ's menus don't track the moue properly - again, probably a Java issue, but still works great under KDE
I had issues with IntelliJ until I switched from OpenJDK to the Oracle JDK. Now it works fine (though a bit ugly).
> Having to "drag" the screensaver thing away is annoying
You're doing it wrong. Just start typing your password and it goes away.
Some of the developers definitely do have a bad attitude, but many are actually quite awesome. Besides, more often than not, their way has turned out pretty good.