Headlight Wiring Q

[indr]

I am redoing ALL of the wiring and am looking to simplify the wiring involved in the headlight circuit, as much as possible.

Here is what factory wiring is supposed to look like:



So, as you can see, one end of the headlight relay coil gets it's input from one of two sources via Diode B. One is the headlight relay switch itself being closed, and the other is a current from the alternator (middle diode in Diode B with the Yellow input wire).

If I eliminate the first input (the headlight relay switch being closed), and just rely on the headlight relay coil being powered when the alternator is spinning, could I get flickering at low RPMs?

Also, another thing that is just baffling me.

The headlight relay coil's other end gets it's input via the Y/R wire from the starter relay switch's wiring. The starter relay's switch is ONLY activated when I go to press the starter button, after which it closes. So, how is the switch inside the headlight relay kept in the closed position once the power input from the Y/R wire isn't there anymore? Shouldn't the headlight relay switch open as soon as the starter relay switch open since there is nothing grounding the coil for the headlight relay switch?

Here is a bigger diagram:

[DaBlue1]

One side (coil) of the headlight relay is AC the other side (switch) is DC. If you look at the schematic, you find the Brown (BR) wire is controlled by the ignition switch which powers the fuse box. That is how the relay switch stays closed after the relay no longer receives power after no longer flows in Yellow/Red (Y/R)

[indr]

So, if the Y/R wire in the headlight starter relay wasn't present, would it still work? I.e, if it was only getting input from the Y wire?

Sorry, I'm very new to electricity.