Disable "vibrate" in lock screen
No, this is not an option.

Actually this seems like a bug as this should be controlled by the option, Vibrate on Touch under Sound in the settings.  Either that, or the option Vibrate  on Touch should remain visible when setting the screen security option to Slide in the Security part of the settings.

You may want to report this as a bug to the Android team using the Android Issue Tracker.