I didn't even have a door on my coop for 7 years. Until I lost one of my favorites.I've not closed my chicken door to my coop. Maybe once or twice in the last 10 years when it was really cold in the beginning of chicken keeping. It's all inside a run. So, you would really have to determine how secure your run is from predators and then decide how many security features are needed.
I'm comfortable with the chicken door being open all the time. I've also never had any predators breach my run.
Now, my heat lamp is secured by 3 different ways to prevent it hurting my chicks.
It's closed up tight every night now!