A typical 8' by 10' bathroom will cost about 2 cents per day.
(Assuming 10 cents per kilowatt hour electric cost. Your costs may vary.)

Any standard floor covering including hardwood, tile, linoleum, brick, etc. Consult the installation manual for specific thicknesses and combinations.

The National Electrical Code requires that the outer jacket on Romex can only be removed inside of a junction box. Since the connections of the heating elements are not in the same place, using single conductor wire allows for making these connections without breaking this jacket.

Although Calorique currently has a connection box which allows for using the system with Romex, this box is intended for use only where local code requires the multi-conductor cable since the box is more expensive and difficult to use.

This spreads the heat out, making it more even, and also allows the heat to enter the room from under a couch without being trapped, which is inefficient.

No.

No.

No.

This protects the operation of the elements. If, for example, a bus bar were severed during renovation work*, the entire element would continue to operate.**
* Always turn off power to the elements when doing renovation work to the floor or the ceiling below it.
** If a bus bar is severed, make sure that the severed ends are properly insulated before restoring power to the system.

The typical 8' by 10' bathroom uses less than 2 amps at 120 volts.