I know this doesn't really belong here, but wiki.kde.org is scary.
keyboard shortcuts: ctrl+f12 brings up the dashboard. this brings all the desktop widgets to the front. whether or not panels should also be raised hasn’t been decided afaik.
thanks to Alex, holding ctrl while resizing allows you to change the aspect ratio. [actually it toggles such behaviour now, depending on the applet's default behaviour]
I think that’s it for keyboard shortcuts. someone needs to add more someday. preferably in a sane manner, not just at random. :) apparently such information belongs in kdebase/workspace/doc - but I’m just dumping raw information right now, I’m not gonna write actual real docs unless someone tells me how :)
oh, and if you right-click on the little gap between two tasks in the taskbar, you get the standard applet contextmenu. this was supposed to also be added to the menu you get when you right-click any task, but I think that turned out to be harder than expected and isn’t done yet.