I think it's a great idea. My initial idea would be to have a google doc where people can signup, maybe 1 or 2 a week? (whatever that doesn't matter) but what I was getting at was simply creating a clear queue for who will upload what video when, plus this way the last question will always be the starting one for the next one, instead of a last question that then have 4 videos start with that one and then you have 4 new last questions that are all different - but that isn't a bad thing either - it just depends how "linear" you want to keep it.

I def think videos should have a max of 5 minutes; however you could maybe do a "weekly" video that is of the longer variety that maybe goes a little more in depth or a story has crossed your plate that clearly justifies more than a 5 min vid. The weekly video would be sort of a "highlighted" interview.

Those are my initial thoughts. I may come back and post again if I have some others as the idea rattles around in my head.

edit:

Should it be long form or conversational

I would say either; I would like the video to be in whatever form the person feels most comfortable with or is closest to their own personality.

edit 2: you can also throw me on a list of participants if you want