It came as a sort of eureka moment as it explained a number of things I'd noticed while flying. Like why is the ball not where I expect it to be when turning? Why are my 45 degree steep turns suddenly becoming 60 degrees and more? Why am I loosing height? Why I am finding it so difficult to keep the plane level in a steep turn? Why do I need so much back pressure?
Don't blame the rudder for that.
Turns steepen because the outside (top) wing travels faster than the inside (bottom) wing. So there's a net rolling moment into the turn. If you don't hold out-of-turn aileron against that, your angle of bank will increase.
Once you have that angle of bank properly fixed, the next thing to concentrate on is the balanced flight -- non-slipping flight. That will (near enough) minimise the drag and therefore minimise the back pressure you need. The yaw budget in the turn has many contributions working in both directions. You will usually need into-turn rudder for the reason I described earlier, but there are other effects: if your out-of-turn aileron creates enough adverse yaw, you may actually find yourself skidding into the turn.
Different speeds and different angles of bank mean the various contributions net out differently. The only useful rule for minimising drag is "don't slip", which is almost equivalent to saying "keep the ball in the middle".