When using weapons, you will have a crosshair and a red line with which you can almost accurately aim. No, sadly this feature will not be in Oni. Matt confirmed this on the forum . There is, however, an internal recording option. But you cannot save the recordings as movie files etc.
Nothing really is known about their departure.
Combining other keys with the movement keys you will be able to perform flips, cartwheels etc. Graphic sprays of blood probably would have pushed the game to a higher consumer rating. It seems that you can't with the current Oni demo although I myself have been able to play Oni with the MacAlly iShock gamepad on the Macintosh. What I did is use the MacAlly iShock Utility to assign keys to the buttons of the gamepad, thus enabling me to play with the iShock. This was not really a fun experience and I had no way to control the mouselook feature.