Raymond, I do not take a lot of video but I will give you two suggestion that may help. First in concerning knowing how much time is remaining for your video I would refer you to Tip #55 that will cover that and tell you how to do it. By setting up your camera to have the video saved to card slot #2 you will always know exactly how much time you have remaining to record your videos.
What I have found as far a video is that leaving my camera in manual focus works much better for me because the camera does not keep refocusing continually which causes problems not only with the video but you can hear the focusing in the audio portion also. I have found that my camera can auto focus much better than I can manually focus so this is how I proceed when recording video. Before I go into video mode I just point my camera at where the action will be and take a auto focus reading because I do not seem to do a very good job in focusing in manual. Once the camera has acquired the focus I turn the auto focus OFF, and now I am ready to turn on live view and get ready to record. This gets me the focus that I don't seem to be able to get manually and it also eliminates the camera continually refocusing and also eliminates the sound that is picked up each time the camera refocuses. Now I am ready to turn on the live view and start recording.
This is what I found that works for me but I will have to mention again that I do not do a lot of video and someone else may have some better suggestions than I am able to give you. When recording, if you need or want to move your camera around for different views be sure and make all your movements slow and smooth so that your picture does not look jerky from the movement. Good luck with the video and I would HIGHLY SUGGEST doing a little practicing BEFORE the night of the show. Jeff