The blindspot monitoring and rear crosspath detection aren't needed, but they are kind of handy. If you are already very aware of your surroundings, it doesn't help that much. I am slowly getting used to the blind spot indicators.
The ParkSense really isn't that critical, because they will have the rear-view camera, but it is an extra safety measure with audible cues.
For me and my wife, the push button start is very nice. She can leave all of her keys in her purse, and take either car (Dart or Charger) without having to dig through her purse for them, and then differentiate between the two vehicles. Just walk up, touch the handle, get in, and push the button.
As Sir Moses said, they need to decide if the convenience is worth the price. To some it might be, to others it is a waste of money.