Cydia keyboard that leaves the middle of the screen empty I can not press the area of the screen where T and G keys are(middle of the screen). As a consequence this makes it impossible to write anything in portrait mode. Is there any Cydia keyboard that doesn't use that region?
It's not longer necessary for a keyboard from Cydia. From iOS 8, there is support for third party keyboards. There are alternate keyboards which can be found on the App Store which take different amount of screen real-estate. One of the smallest keyboards available is the Minuum Keyboard.