The body is Aluminium, the heat core is ceramic with embedded electric elements.
Yes, they have a built in 7 day / 24hr programming system.
They are manufactured in Spain.
The runnning costs and energy use will depend on how good your property insulation is, how energy efficient your windows are, your electricity tariff and your thermostat setting.
Yes, they are 100% efficient. This means all of the electricity input is converted to heat output.
They can be used with economy 7 but we don't recommend it. Because the radiators are direct acting and give greater control and comfort, they need to use electricity when required. On Economy 7 the electricity is cheaper overnight but typically more expensive at other times.