Over the years I have used a variety of hollow wall anchors. But before I get into my favorites, let me ask, is the wood that makes up the door thick enough to keep the holder from punching in at the bottom of the hanger? All of the weight will pull the top of the hanger out, and try and push the bottom of the hanger in. Maybe you could consider a backing plate to spread out the load a little if you are worried about thin door wood.
First picture is of my favorite anchor system. Down side is it will leave a hole about the size of a pencil or maybe your little finger, if you use the large ones, if you remove the hangers in the future.
Second picture is probably my least favorite. I've seen them slowly pull out when the wall gets hot.
Third is OK, but again the hole needs to be large enough to pass the wings. And if you unscrew the screw too far the wings will fall down in the wall cavity.
Forth picture is a good one except for when it comes time to remove it. I usually drill the top off of it and knock the rest of it inside the cavity.
Interesting to note, anything that falls down inside the door cavity will rattle a but as you drive down the road.
Hope this helps in some small way.