Course work content varies from class to class based on the equipment used by the class. They are not large, and provided you don't allow the program to take over other player's format, having all of them installed lets you take advantage of which format is best for the program and the condition of your connection. Some of the viewers make a temprary copy to allow you to back up. For stored programs, that are short enough, the entire program is downloaded to your disk so that you can view it without being interrupted due to network problems. Once you have viewed the program it is safe to delete these files, or save them for later viewing.
Compression is done in 'real-time'.
For live images there is some delay from the actual event, but those delays are similar to satellite and internet delays in general. The compression process and encoding process for live events do not significantly delay the broadcast. At this point ITC does not have enough experience to recommend equipment or software. We recommend you contact the University Library Digital Media Lab for these sorts of recommendations. Right now, not a lot.