Is it possible to hide a Yakuake's title in fullscreen mode?
At screen of notebook it takes up quite a lot of space.

If Yakuake doesn't allow to customize fullscreen interface separately, can I hide title totally? Maybe by editing the skin?

According to the Yakuake maintainer, you can "hack the title bar to be 1px in height by reducing the height of the skin's background image" to do this.