Look up a parts list for your model of water heater on a trusted site such as seasrpartsdirect

Once you have the GE part number it’s easy to find other compatible parts.

Ahh, where local code requires conduit. (Instead of allowing Romex)

I might be seeing a grey wire and a white wire, so there might be the intent that grey is hot and white is neutral, but an electrician should check.

I’d think, make a template with cardboard or a scrap board, in the same way as you made the shelves (slightly too small). Then use a framing square, or ruler against the wall to draw the exact shelf dimension 1-1/2” shorter. Then put the template on the finished shelf and use the same framing square to draw out the exact dimensions on the actual shelf.

That’s a lot of wires. Is this another country?
I’m only used to seeing ground, white (neutral), black (hot) and possibly red as an alternate hot. And a switch with (3) wires is usually a 3-way switch, meaning there is a 2nd switch that also controls the fan.

That’s pretty interesting with the electrical tools and connectors. Ultimately it depends on the type of work wanting to do. 1/2” drive is better for larger automotive bolts, such as lug nuts.

For the most part, hex (6 sided) sockets are better than 12-point sockets, as 12-point are more likely to strip a bolt, so I like seeing the hex in sets like this.

This! There are screens, like kitchen faucet aerators, between the hose and washing machine. I had to clean the screens in an LG washer. It’s helpful to identify if the hot fills faster than cold. (Meaning cold screen is clogged)