Just thought I'd mention that there's a couple of tools out there, to get, "sloppy scrollwheel focus".
Katmouse is pretty straight forward, although if you don't want it to hijack your wheel button, you'll need to disable that in it's preferences.
http://ehiti.de/katmouse/DeskAngel doesn't work perfectly with bbWorkspaceWheel (you'll need to restart blackbox, after starting DeskAngel) but it has more features and doesn't need to be installed (great if you put blackbox on a flash stick).
http://www.softpedia.com/get/Desktop-En ... ngel.shtml