I know it's probably not best practice but at traffic lights I usually put it into P with the handbrake off.
Saves blinding the driver behind me with my top brake light.
I would never use N in everyday use.
I don't think that Neutral should be used when being towed in an auto either - it knackers the 'box......
My previous two auto cars had release buttons to totally disengage drive for towing - NOT my present Auto Focus though.
There is no law about putting the car in neutral at traffic lights, but your partner is right. Using neutral and the handbrake is better practice, and safer, than the modern habit of using the footbrake. It doesn't take any longer either. In an automatic, it is less dangerous, but the police sometimes check automatic cars in the expectation that the handbrake will have become inoperative due to neglect.
So Ian every time you stop at traffic lights you flash your reversing lights twice at the car behind, That must be worse than having your brake lights on.
The correct procedure is to be in nuetral with the handbrake on.
Neutral should not be used during normal driving. One could come off the Dover ferry and drive all the way to Scotland using just Drive, or reverse if needing to go backwards.
The mechanical set up of the gearbox is such that the oil continues to be pumped around the box when in drive - even when stationary. This has a beneficial spin off as it aids the cooling of the box all the time.
The car fights no one during this type of gearbox and 'creep' is needed otherwise the car will drop below the laid down engine speed and stall.
As long as the car is driven in drive and then stopped on the footbrake - apply the handbrake and wait for moveoff. Keep you hands off the selector and enjoy the advantages of a modern, sophisticated gearbox system.
The only tips to offer here are that when drive or reverse is selected depress the footbrake and all you will feel or hear is a dull cushioned thump. Normal.