i dont think there would be any problem, though if ur shifting from N->D at 60 kph and above, press the gas slightly before shifting from N->D so that the engine wont pull the car back so much. after ur used to it, u can even get ur car to shift into the right gear (it engages the right gear now most of the time for me)

i do D-> N and N->D quite often to save petrol...so far no big problems yet...so far can tarik extra 40-50 km la this way.

D->P tried at 10 kph before, car engine went dead and out of control (steering lock, car electronics goes off, lots of scary noise coming from the front).