It really depends on the vehicle. Some vehicles read the speed and decide which gear to go into. Most don't though
I only Engine off coast when I know I'm gonna completely stop, such as in my driveway.
One thing about shifting into neutral, only do it when your below 30 as a guideline. You can shift into neutral at a stoplight for instance, since you will use less fuel. While in Drive your engine uses more fuel to keep it running since obviously it's still trying to move, but your not letting it. so in neutral, it eases the burden, and you use less fuel. But when you put it in drive, wait till the car starts moving on it's own before using the gas.
