This almost drives me mad! I want a "Save this as default" button somewhere in the settings, and then I want it to always open windows of that size. Also, I never want Dolphin to open the terminal window when I start up dolphin - no matter whether I used it last time I used Dolphin.
I want a default window size. I also want to be able to change the size of the windows (as I can), but that should not be remembered when I close the window...
On Kubuntu, systemsettings->Window Behaviour->Window-specific allows you to configure specific parameters for windows for any particular application, such as initial size, position, etc. Presumably other distros have a similar interface to what
should be provided by kcontrol if it still existed.