TechSmith's latest version of Camtasia for the Mac brought the product into near parity with the Windows' version. There are a few things that are either easy to overlook or not yet documented that I think are worth knowing about.
You can delete that drop shadow effect from the timeline. Open the effect clicking on the white "up arrow" on the callout. Then right-click directly on the effect inside the callout and select the "Remove Effect" item from the context menu. If you want to remove all effects you can do that by just right-clicking on the callout itself and use the Remove->All Effects item. You can also delete any effect from the properties pane, just click on the X that's to the left of each effect name.
If you are positioned on a break with open space available to the left in ALL tracks, you can also Shift-drag to the left to move all the tracks at once.