The reason for the shutdown when opening the door is because of the MyKey technology.
The instrument cluster remembers key IDs. As far as the instrument cluster goes, it considers a remote start fob as a key.
Now, say I am a young teenager looking to borrow my parents Focus. They have given me a programmed MyKey with speed limits, etc. If I decide to start the car with a remote start fob, it will shut down when I open the door so that I have to use the MyKey to start the vehicle.....and I am forced to drive with limited use. Now, if the remote start was programmed so that it stayed running in a seamless operation as we are often used to with older remote starts, I have the ability to start the vehicle with a remote start and even though I have the MyKey in my pocket, the car is still running off of the non-limited key ID that was the remote start fob. The young teenager can bypass the MyKey system completely!
That is why the vehicle shuts down when you open the door. It used to be bank 2/option 7 for the one button remote starts to shut down this feature but I'm not sure how to do it with the new ones. I'll keep you guys posted when I get a chance to play around with one as I usually turn this feature off for most people as I have found that 95% of the people will never use MyKey.