Having trouble Getting my continue button to change states and then be clickable after a variable has changed.

The "Set AllWatched to value true" trigger will never execute, because at the beginning of the Continue button's timeline none of the T/F variables are true. Try adding it to each of the layers. Depending on how you determine that a video has been watched all the way, you need to adjust the triggers to execute to "when slider layers timeline ends" , or "when media xyz completes".