Are you actually suppose to connect your circuit to the earth?
Nothing you do is going to change it's potential significantly.
Having Ground present doesn't stop you getting a shock !
This can be very large if the earth connection is taken from two points in the order of half a mile away.
As is the case with the UK mains earth being taken from the incoming neutral.
No.Wiring regulations state a local earth bonding must be used. Usually taken from the gas supply pipes.
There is a potential of about 5 to 12V AC between neutral and ground. You can, if you like, rectify this and use it as free power because it doesn't go through the meter
and has a route back to the supply in the event of a fault
I had a torch bulb in my bedroom powered this way when I was a boy. Never got much light out of it.
That is not correct. In one house I had the mains was on a spur along our row of houses. One day the neutral developed a fault and got disconnected. The result was that we experienced twice the mains voltage in our houses.This caused lights to fail and also electronic items like the Hi-Fi amplifier which was being used as a baby monitor at the time.We got twice the voltage because the return was then coming from one of the other phases. If the neutral had been connected to the ground this would not have happened.