You need to blacklist the WASD keys through the Do-not-pass section.

http://www.solidice.com/keyclone/tutorial/index.html

Clicking to cast is frankly the wrong way to do it. Clicking is slower than keypresses and often far more inaccurate. It is usually reserved for infrequent actions.

While there is the ability to pass mouse clicks, it is not something that can be "always on" with Keyclone. Even if it were something that was always on, it still wouldn't work for movement as your clients will never be 100% in the same exact position. You will need to use follow.