I know you don't know what henderson knows but as soon as you ignore you don't know what you should know, then I guess you are fine.
Trading is a bit like learning how to ride a bike. You start with the stabilizers (small size) to keep you from falling off and hurting yourself. After a while you get to learn about balance (market structure) even though you did not intentionally set out to learn about balance. Some of course will then pedal so fast (over trade) that they will have a few crashes with the odd few doing serious damage (blow account). When you can pedal along with no hands (not depending on TA indicators) and turn the bike (enter a trade) by just moving your body (without thinking too much) you are then an experienced cyclist who knows exactly when to put the hands back on the handle bars (exit a trade) due to seeing what is in front and to the sides. Whilst many cyclists (volume) gather at times for a big race, the cyclist who want's to win does not care how many are there but he does care about the few that are able to keep ahead of him. We are but pawns in the big game of financial chess. We must know the moves that will get us in a state of checkmate and avoid them at all costs.
I know that every trade is a loser until it is a winner. I know that when I lose it is because I entered at the wrong TIME. I know that if I exit a winning trade before TIME I will not make as much as I should have made and this will make it very hard for me to make my winners multiples of my losers. I know that the ONLY way to make money trading is to lose small and make sure my winners at at least 3:1 compared to my losers with 5:1 as an achievable target. Overall I know that I know nothing but as every other trader knows the same I am on a level playing field and all I need to do to come out ahead is to have enough money to start with so that I know I can do at least 100 round trip trades in my chosen market.
Yes there are 'official' marketmakers on Globex - without that rule they couldn't, for example, constantly stream quotes due to the CMEs messaging policy, from which they are explicitly exempt. There is really not much information available on that topic on the cme website.
Interesting reading but I personally would leave it at that. I think it is not required knowledge for the average trader and I doubt very much that it will yield any valuable information for same.