The answer for OP is no, there is no way to completely disable the existence of the floating keyboard.
There are two triggers for floating keyboard. Either you're resting your hand on the bottom right such that the keyboard switch is being selected and then activated OR you are somehow dragging fingers on screen in such a way as to be perceived by the touch screen as a pinch. My guess is the pinch gesture is what is occurring.
Only other fix I can think of is to install a completely different keyboard. I've never found one that I liked though.