How do you determine domicile?

Solids have fixed shapes and volumes. Liquids have more or less a fixed volume (but may be moderately compressible). They take on the shape of their container. Gasses take on the shape and...

If you are divorced there can only be one domicile resident

That is a true statement. We make choices and we are judged by the choices we make.

Both are true. It is a two-way street.

Yes. Buyers want a product and those that sell it regulate how much of it they sell to the buyers, therefore controlling the supply as a result of the demand.