If this comes off as harsh, I apologize in advance.
You have written much here, and obviously you have given it much thought.
Time to stop writing. Time to stop thinking.
Commuting by bike may or may not be for you.
There is one way and one way only to find out.
Throw a leg over the top tube and hit the road.
Cover the essentials..
lights front and rear
helmet
eye protection
gloves
rear view mirror
flat tire kit
Here is my challenge to you.
In the next ten days, ride your bike to work.
Then let us know how it went.
fat biker