Hello, I am interested in learning about accurately setting the gain structure on my gear. From my internet research on this board and other internet sites, I decided to map out the steps as follows:

Get a one of the loudest musics in my library to use for gain staging.
Turn all gain stages down to the left.
Software/Serato: Set auto-gain, and set master software output at 12.
Channel/Input: get the faders all up, then play the music, and for each channel, set the input gain/trim to peak at 0db (greens) before hitting the amber/reds. Once this is set, then pull back down on the fader a bit to about 95% of its volume capacity.
Master volume: repeat the same process with the master volume, and not when the less hit 0db.
Subwoofer: Turn up the volume on the subwoofer to 0db or until it hits green or until the limit light appear, then dial back a bit.
Speaker/Amplifier: Turn up the volume on the speaker to 0db or until it hits green or until the limit light appear, then dial back a bit.
External Mixer: repeat the same process for each channel on the external mixer as done for channel/inputs in #4 above.

Now my questions:

A. Is this the right procedure?
B. To set the gain structure accurately, my research on this and other sources indicate that you have to get a loud music or louder point in a track. How do you get this? I can sort my tracks by dbs, but will that be accurate enough?
C. The advice is to turn all gains down low, but do I need the speakers to be playing loud before setting any of the gains? For example, to set the gain structure on the Master Volume, does the speaker need to be turned on? If so, then I would be bugging my neighbor.. lol lol.
D: To set the gain on the speakers and subs, I do need to supply it with input/music… assuming I am using one of the channels on the controller, should I set the volume on the fader all the way up or just use the master volume?
E: And finally, once I set the gains, which of these MUST be left absolutely alone and not fiddled with?
F: If I want to increase the volume, where should I do this: on the channel fader on controller, master volume or the channel volume knob on the External mixer?
G: Finally, the Master volume / input channel knobs or faders on the External mixer replicates what is available on the controller? So which one should be using to control the main volume for instance? My sense is it should be the main volume on the external mixer….

Sorry for these many questions .. but I appreciate your assistance in advance..