what's up dude. when i do live video i always take the footage back to the studio for editing. i NEVER do in-cam editing. sounds like that is what you are going to be doing. i will tell you how i run my setup....in basic short-to-the-point most of the time shoots.
usually 2 or 3 cams. we do bands and corp. stuff. for lectures what i do is this;
1 cam as close to center of speaker as possible on tripod and i connect a wireless mic to their lapel which records direct to tape. the 2nd cam will pick up the ambient audio of the room and i will have this cam to the left or right of the stage, also on tripod. 2 cam operators watch each other for the zooming and panning, as they will occasionally get audience reaction. always make sure both cams never film the same thing....one on speaker, one on person asking question. what i have also done, if there is a Q and A session, is hook a wireless lapel to the speaker cab and balance for sound. that way as the person is given the mic, my other lapel mic will pick that up very well to the 2nd cam.
for switching live, acting as the TD (technical director), you will need to connect the cables for video and audio feeds to the mixer so you can have the 3rd person edit live. not sure how much this is, as i always just bring my tapes back home and edit in a controled environment.
for extra lighting, if i need it, i have a couple 500 watt studio lights complete with the barn doors and filters so as not to melt everyone.