My 2011 was hit from behind by a 4X4 diesel pickup while I was sitting at a traffic light. Both vehicles left on tow trucks so it was a fairly hard hit. The pickup driver was surprised that his air bag did not deploy. I drove the LEAF out of the intersection to a safe place to park without incident. It was technically repairable, but the other driver's insurance company declared it a total loss because they thought they would save money (used prices were depressed because there were a lot of LEAFs coming off lease and flooding the market). I don't think that the hatch (or any other door) being open will prevent the car from going into drive, but I will check my 2015 when I leave for work later this morning.
The battery is under the passenger compartment so it was probably not damaged by the accident since it does not extend beyond the rear seat. However, it could have been damaged by the salvage yard. In my case, the mounting brackets for the onboard charger were bent, but the charger appeared to be OK when I went to the repair shop to look at it after they removed the interior panels so they could finish their repair estimate. When the insurance company decided not to repair it, it was moved to the insurance company's storage lot. I considered the feasibility of buying it back and making it into a small flatbed pickup since it had a relatively new traction battery, but the storage yard trashed it. When I went to look at it, the front end had been damaged from being handled by a big fork lift and the interior had grease and dirt everywhere. The car would still go into READY mode, but I had to give up the plan to buy it back due to the damage while in storage. Once I saw how they were moving it with the fork lift, I was also concerned about possible suspension or traction battery damage from the forks since it is such a heavy car.
Edited to add: I just tried my 2015 and verified that it will go into Drive or Reverse (and actually move) with driver door or hatch open. Is there any information on the dash display when you try shifting into drive or reverse? There are two air bag lights--one is a warning in the dash in front of the driver and the othe is an indicator that shows the passenger air bag status below the radio/navigation unit. The passenger air bag status light is on if an adult is not sitting in the passenger seat.
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015