Let the transmission do the shifting. If it starts to hunt pull the lever and hold the gear to the top. 3500 to 4500 rpm is normal climbing a hill. Do not make it a race. Go a little slower is OK too.
Go a little slower on the decent. Down shift to get about 3500 rpm of engine braking when needed. Do not ride the brakes to maintain a steady speed. If you need to slow up use the brakes moderately firm to drop 10 to 25 mph then let it coast back up. Brake before the curves then coast through them. Don't be tempted to touch the throttle as you exit a curve... let it coast up to speed again.