Some W/A adaptors also will not let you zoom through the whole range without shifting focus. Also it's one more piece of glass to loose light and degrade the image.
Danger of zooming in too tight is loosing the action from the shot. That's the biggest advantage of having two cameras for these kind of events. You can keep one wide and use the other one to try and get the close ups of the action.
Your basic lens is fine unless you are using a 16:9 camera in 4:3 mode, in which case you need a zoom through aspect ration converter.
I did centre ice level hand held cam for years and couldn't have done it without zoom. Hockey is a fast game and you need a good zoom lens to cover the action properly, as in follow the puck.
I do amature Soccer games. It's a real trick keeping the correct balance of a good field shot and action shots with not zooming in too much. Soccer like Hocky is a fast game. Tight shots while panning leaves allot to be disired.
Ah ha! You are right about that BUT I negelected to mention that there were three tripod mounted cameras up above the stands, one at each end and one at Centre Ice, switched by a guy with years of hockey coverage experience. I doubt if my shot was ever on screen for more than a few seconds. For what its worth, I always used the same Canon 17X lens, usually zooming manually by keeping my finger and thumb on the zoom ring. No way you can be that close to the action and keep the puck centred with power zoom.