eeenok yellow-green means earth everywhere, but this is 2×live & 1×neutral. they used the same three wires they put in other products because lazy & stupid.

eeenok there is no dimmer for LED. the effect of reducing voltage depends on the design of the circuit in the LED. it's very likely reduced voltage has no effect, because the circuit still has all the power it needs

eeenok you probably shouldn't rely on it being electically conductive OR non-conductive. basically it's non-conductive, but if your work is critical or high-voltage a mica sheet etc is more reliable than glue

eeenok there are three options. the cheapest price is displayed but a different option is selected. change selection in cart

eeenok obviously it supports at least two controllers, since that's a purchase option. it probably supports more, since the one circuit will be used in different products. i'd be surprised if both controllers need to be the same code, so switch can probably remember about eight. and since switch supports "latch" mode, you can probably use one controller as on and another as off. exact answer is hard to find the cheapest way to buy controllers is with the initial purchase, so try to find one with the number of transmitters you want

eeenok you want jog ("inch mode"), not toggle. the instructions say this is 1+2, but the circuit board says it is no jumper. you'll need to experiment

eeenok (1) try re-binding remote (2) check your 12v supply to receiver isn't noisy. power going to load can be noisy

eeenok i don't think it can "change state" on power-up (NC starts connected, NO starts disconnected) but your equipment will start on if you connect to NC+COM and use OFF to turn ON. equipment will be on if right side has power, even if receiver has no power. if your equipment is 12V, then power receiver AND NC+COM with same supply and equipment will work when providing 12V