I had better say something before this gets completely out of hand. First, I would never, let me repeat, never advocate aerobatics in a non-aerobatic aircraft. Period. You are asking to become the next winner of the smoking hole award. Can it be done, sure and probably has been. Same as the guy telling me the story about doing a half snap to inverted and then pushing and adding top rudder. He couldn’t figure out what happened until I explained that was a nice lomecevak. He was flying a PT-22 at the time. Should have killed himself.
The above roll description should not give you negative g. If anything you should get a 0 float at the top of the roll, but no negative. in the Eagle, miminal rudder is needed just enough to keep the nose on line. In the Extra, CAP or Sukhoi, just slam the stick over and you will be done before you can saw “wha happened?” The 7ECA, and many other aerobatic birds use the 0-320 or 0-360 engines. No fuel injection here. Yes, the engine will sputter at the top of a loop an immelman and a few other manuvers. But they do them just fine. Carb engines can be flown in the acro enviroment. In fact, in order to have fuel flow in a fuelie, you need positive fuel pressure, i.e. a fuel pump and a flop tube in the tank. Look at the Pitts or Eagle.
If I understand Ashley correctly, he is calling for slow roll in which the aircraft should appear to climb slightly, roll and return to the same altitude that it started from. Check what I wrote above, use your hand to trace it, and you should find it is the same thing. Pitch nose up, start the roll, notice at this point the nose has gone above the horizon. At inverted, you should be level, don’t let the nose fall through the horizon, allow it to sink! As you come through, notice the nose has come back to the horizon as you come to level. Rudder keeps the nose from dropping and getting away from you, elevator does the same thing. Remember you are wanting to control your airpeed and avoid any lost altitude. Allowing the nose to drop while you are at inverted will cause airspeed to build up and you will need to pull hard to return to level at the end.
Acro is the best. You learn to fly in all three axis and become very proficient in aircraft control But you must, repeat must, have compentent instruction before doing anything on your own. That is only you should be flying anyway.
Now I will go away and say no more. Besides, it is time to buld stuff!