As I've written before, there are many elements hidden within Final Cut that give hints about possible future directions the application might take.
One feature implemented but not enabled in version 10.1 and 10.1.1 is the ability to move markers along a clip:
It is possible to modify an installed copy of Final Cut to turn this feature on.
Note that there might be a good reason why Apple didn't enable this feature - perhaps beta testers suffered mysterious crashes due to an odd clash of code when the feature is enabled. Maybe they want to make the feature better before making it public (selecting multiple markers, making markers draggable to other clips). I don't know. I made the modification in February on my main Mac with no problems, but I can't guarantee all will be well on your system.
The preference is hidden in a property list document hidden within the application - that means to enable it, you will need to use another application to directly modify your copy of Final Cut Pro X.
How to turn on Final Cut's Movable Markers feature
If you have enough disk space, install Apple's development suite - Xcode. It is available for free from the Mac App Store. If you don't want to use over 2GB of storage, search the internet for applications that can edit .plist documents or 'Property List' files. An example is 'Pref Setter' from Night Productions.
Quit Final Cut Pro X if it is open.
In the Applications folder, control-click (or right-click) the Final Cut Pro icon and choose 'Show Package Contents' from the context pop up menu.
Navigate to Final Cut Pro.app/Contents/Frameworks/TLKit.framework/Versions/A/Resources
Drag a copy of 'EventDescriptions.plist' out of Final Cut to another folder or the desktop.
Duplicate 'EventDescriptions.plist' in the Finder using the Duplicate command in the File menu (or option-drag it to a different folder). This unmodified version will help you restore Final Cut if needed.
Open 'EventDescriptions.plist' by control-clicking (or right-clicking) its icon. From the context pop up menu, choose 'Xcode' (I need to do this on my Mac because I have multiple applications that can modify .plist documents).
In Xcode, expand the 'TLKMarkerHandler' section by clicking its grey disclosure triangle.
Change the 'NO' to 'YES' by clicking the pop-up control to the right of the 'NO'
Save the file to keep the change to 'EventDescriptions.plist' and quit Xcode.
Drag the modified 'EventDescriptions.plist' into Final Cut Pro.app/Contents/Frameworks/TLKit.framework/Versions/A/Resources
You are likely to get an alert stating that 'Modifying “Resources” requires an administrator name and password.' - Authenticate using your password.
When you next open Final Cut Pro, you'll find that you can drag markers along clips and also drag them off clips as shown in the video above.
Please remember MODIFYING THE INTERNALS OF FINAL CUT PRO X CAN DAMAGE IT - be careful with the changes you make. Make original copies of any elements you change in case things go wrong. As a last resort you can delete your copy of Final Cut and go to the Mac App Store and reinstall a fresh copy if needed. To save that time, be careful as you make changes.
Bonus Tip - Less rounded corners in the timeline
Sharp-eyed Final Cut users will notice that the timeline shown in the video looks subtly different: the clip corners are less rounded than in the stock version of Final Cut Pro X. I got this result by changing values in the 'CornerRadius.plist' file listed above in Final Cut Pro.app/Contents/Frameworks/TLKit.framework/Versions/A/Resources - using width settings of 0, 0, 1, 1, 2, 2, 2, 4, 4 for items 0 to 8.