They are all fairly reasonable. Personally I like the 7th tackle for the kick out on the full. I think it's a clear and easy rule to follow. A bit like the advantage rule that was introduced. There is no interpretation required. I think the difficulty with a kick going dead in goal is that you could have an awesome kick that stops centimetres on the otherside of the dead ball line. The intention was to stop in goal not kick it dead, but it would be severely punished if you went back to the place the ball was kicked.
But any other rule would need interpretation to decided whether it was a time wasting kick or not. This is a good middleway. It's not an over the top punishment for a kick that just fails to stay in goal.
Other than that I think that it looks increasingly like the NRL are wanting to do away with scrums where ever possible. Possibly because they don't like them, possibly to create a more stark difference between the two codes. Leaving Union with the scrum and making out League to be a more set piece orientated game.