You can modify the time delays KMouseTool waits, for both clicking and for dragging.

It's best to practice clicking with KMouseTool using its defaults first. You may especially want to leave Smart Drag disabled at first. Then, once you are comfortable clicking, move on to practicing Smart Drag.

When using Smart Drag, it may help to enable the Audible Click

When using the Audible Click, you may need to speed up KDE's audio response.