Fredrick I have a personal plea....
"Deselect this option to disable all caching functionality" drives me crazy.
It goes against every UI guideline I can think of to have a check box described solely by it's negative action. It reads totally non-intuitively and having a big giant "ENABLE" button between it and the save changes button just adds to the confusion. Since more than one person I've shown W3TC to has instantly assumed that button was to enable W3TC not the Preview mode. I know it's all there if you read it, but it's not intuitive.
Please consider changing the check box to read
Enable W3TC (Deselect this option to disable all caching functionality)
Active (Deselect this option to disable all caching functionality)