You have so many questions and I understand what you are asking however it will be impossible to explain all your question on a technical forum without writing a book.
Breaking it down in several areas would be the best thing. Maybe you should start from the ground up and go from there.
Although I'm into photography for over 40 years I'm still learning.
Let me explain how I have learned to use flash and you might find some answers in there;
Lets pretend I just started out a year ago and my wife bought me a ton of stuff! (Sounds familiar?) It does not matter what brand names or if it is a small camera flash or they are studio lights! Just lets say it's the best of the best and can do anything you can imagine but you don't know how to make that work! So let's go on a dream:
I decided to start off using a one flash/strobe for off camera work. Everything I did was in manual with the use of radio triggers, no TTL no tricks no cables. Now I knew how to set it up technically and made it fire work with my 2 Canon and 3 Nikon camera's (My wife loves me), considering sync speed and the channels of my remote it worked great. Also started to use a flash meter that came with the package so I knew what Aperture I had to use. I had to figure out what gave the best lighting using just one flash that had nice soft lighting so I used an umbrella for several months before I added a second flash for a hair light. The question now becomes what is the best way to use a hair-light so I researched it and choose a grid to have a controlled bundle of light that did not interfere with my main light. It made me realize that combining two lights I had to make sure the main-light was stronger, figure out where to put the light and how close to get the right softness. All this is part technical and part creativity but one step at a time.
As you can read that starting from no lights to two lights and knowing how to do that technically and creatively took some steps and adding a step made me backtrack several times to make it work. Yes the receiver of the second flash had to be set to the same frequency oh I could have used the optical slave too bla bla bla........
This is where my advise comes in;
Take ONE light (It does not matter if it is a speed light like your Canon flash or a studio flash like the Einstein) and first learn hot to set it up and fire it with the equipment you have.
Next step is how to meter the light.
Next step is to figure out how to light something creatively with that one light.
Extend your knowledge using a light-modifier (Umbrella, softbox etc.)
Add another light and start from the beginning.
That is how you write your procedure and gain your knowledge, ONE step at the time. If you want the fast track you have to hire someone who can show and tell. But figuring this out by our own gives the most satisfaction and will stick better.
Lastly everything about creative and technical photography has been written down somewhere if you know where to look and take ONE problem at a time to learn the needed skills.
It's all about doing things step by step, ONE step at the time.
http://OCFworkshop.com has a lot of starter tips. (Shameless plug for my website)