Let us remove our companion's helmets/caps/hats. Is ridiculous how they must be forced using a head item if you use it on the inventory menu by mistake. If you try to remove from their inventory a messages pops up "you can't change a head item" or something like that. You only can replace for a different one, it has no sense at all.

You can go into options and select view the helmet or not. It won't remove the helmet, but will show your companions faces even though the helmet is on. I did that as you spend to much time talking to them and would rather see their faces too😀

Is the motivation to see the companions face?  There is an option in settings that allows you to disable helmets for both yourself and companions.  Or is it some role play objective?  I am just wondering why you would not want the helmets armor and skill boost.

I'd like to remove armor from a companion and use it for another. As it is, I have to replace their armor with other armor that I keep in my inventory for this sole purpose. It would be easier to just be able to unequip and have them revert to their default look.

Agreed, it's ridiculous that I can't drag it off them once I've put it on them. It's just a dumb mechanism.