Dan:
Sorry, I forgot your other questions. Yes, normal residential service in the U.K. is 240V 50Hz 2-wire with a grounded neutral.
Except for a few single-phase lines to remote properties, all low-voltage local distribution is 3-phase 240/415V Wye with a domestic service just tapped off one phase.
Three different grounding ("earthing" in British terminology) arrangements are in use. Take a look at "Non U.S. Visitors - A question" (currently pg. 4 General area) where I explained them.
