It takes so much time and extra clicks to manage the tags associated with an Article or Event. What you gave authors a search interface to easily find and add tags. For tags that are selected, adding an "X" to each to quickly remove them would be useful. The tree view could still be available as an option to, but I doubt it would be used much. I have attached a quick sketch to illustrate my idea.
|Which sport(s) does this apply to:||Not Sport Specific|