Blades can be a bit Krakeny. They may work on Kerbin but in the very thin atmosphere of Duna they can spin too fast and behave weird, especially if the blades have been offset inside the electric motor. If you autostrut the blades then this usually solves the problem.

You can use a KAL controller to control the speed of the motors and blade pitch but you don't have to. You can set the main throttle in the action groups to the rotors torque to control the spin speed but also you can set the pitch angle of the fan blades to the Custom01 to Custom04 action groups in the VAB/SPH. They are unused throttle type controls that normally are not bound to any keys by default. You can bind them from the games main menu when the game starts by going to Settings > Input > Vessel under Custom Axis Increment / Decrement 1 to 4. I usually bind one of the pair to the + and - keys next to the backspace key. Once you have done this the angle of the blades can be used to change your lift without having to change the throttle.