Let the soil "completely" dry out. Mine gets watered ususally once a week, sometimes it's once every two weeks.
Not if the soil is fast draining with a small pot that has about an inch for the roots to roam. I have had my madagascar palm for around 15 or so yrs and that's how I always water it. Keeping it in a small porous pot with good draining soil helps it to dry out faster. By not giving the right amount water, roots can dry up and die like what I believe happened to yours.
What have I got to lose. I guess your right you thank it will staten out it seems to have a curve in the trunk.
I am going to have to cut off the part that has gone soft and cut back on the watering until I see some life. This is a long shot but it is what it is. A new plant may be in order.