It is impossible to say for certain the earthing system without being there to investigate.
I'm wondering if that earth you moved was the earth from the head to the terminal block, looks the correct length and something has been used through the two screw holes.
Yes you can cut it and work the wrapped bits off. If you keep it hot enough you should be able to work them off with long nose pliers. Be careful as melted solder can flick up into your face.
What are you considering as Part P training?
The City and Guilds 2393-10 is nothing more than an exercise in the Building Regulations it is not going to make you an electrician so what are you looking at?
The circuit board from top to bottom ; capacitor, resistor, resistor, capacitor, resistor, capacitor and resistor. The two square parts are bridge rectifiers. The larger part appears to be a relay.
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