I generally agree with the idea of not using duel rates when learning an airplane. You can get in to trouble if you get the wrong rate switch in the wrong spot at the wrong time. I've seen guys snaproll in to the ground because they were on high rate elevator at the wrong time.

As for rate switches being useful, if you are doing some of the advanced maneuvers, they are pretty much manditory. My Cap had big throws on the elevator, rudder, and ailerons. If I tried to land that thing on high rate elevator, a snaproll in to the ground would be almost certain, and that's WITH 50% expo. But that high elevator throw was just the ticket for a good blender or lomchevak. So I took off, flew most maneuvers, and landed all on low rate elevator. I only used high rate for some specific maneuvers when I needed the extra throw.

As for expo settings, I do actually use a lot of expo, as much as 55% on some of my planes. I've also not noticed a sudden step, but even so, I'd probibly start with around 25%. Much below 25% and I'm not sure the expo is doing enough to be noticed much at all.

Since you're not at the point where you're doing those maneuvers, I'd say tune down the control throws a bit, dial in a tad of expo, and go fly, and don't worry about the swtiches for now.