Yarbles,
Disclaimer: I am not a trainer, but I feel I've accumulated a lot of experience on how to learn ACM.
Film those encounters where people do stuff you don't understand and look at it from THEIR first person perspective, keeping your own plane padlocked.
I find using the first person and thinking through the steps helps a great deal. Doing this (looking at first person, not necessarily through film though it can help), I finally understood:
1) How a rolling scissors actually looks when you're flying in one.
2) What a lag displacement roll is (a barrel roll variation - I was doing it, but I had no clue I was doing it).
3) How to use the barrel roll suite of maneuvers on an opponent. There are so many variations on the barrel roll that you can use this maneuver in basically any situation. The difference is in DEGREE - how much G to pull, how much roll... etc
As for everything else - you're fine on knowledge. All these are set piece maneuvers - they do not specify degree (how MUCH bank, how MUCH G to pull, how LONG do I hold it, at what point do I enter the turn). This you have to find by experience, but it's well served if you keep a few main goals in mind.
1) Reduce angle off tail when the bandit's too close and your nose isn't in position for a shot. You do this by using any of many lag style maneuvers from basic lag pursuit to high yo-yo to lag displacement roll.
2) When going for a tracking shot, align your wings with his.
3) Control closure using maneuvering first, throttle second.
4) Pull lead only when you are going for a shot.
5) Store energy by climbing.
6) Convert energy into angles by turning nose low.
7) The easiest shot comes when the opponent is slow.
8) The hardest shot is when the opponent is fast.
My thought process is rarely "what maneuver would be good here" rather... I think about those 8 points and fly my plane accordingly. To be more accurate, I don't even really think about those 8 points, I intuitively know them from flying that way for so long that I act on instinct according to those points.
Nowadays, I find that I die mostly by being stupid (which still happens quite a lot mind you), not by losing the ACM fight.