Answers (at least, what I think they should be):
1) First off, I think we should be called HenCon like you've suggested or HensonCon (both being short for Jim Henson convention). We should most likely do that and say that we cater to a variety of Henson/Muppet/Sesame fandoms all in one or we resurrect the name MuppetFest, but maybe add the word 'fan' in it to make sure we are a fan-run thing and, elsewhere, we put emphasis on our span of fandoms. We should also add in that, while we aren't associated with them, ToughPigs has a wide number of adult fans that might also be excited to come. Adding that together we probably have over 30,000 to 50,000 fans. Just my guess, because ToughPigs doesn't have a place that keeps track of how many members they have. We are a small group, so just kind of getting some statistics for you.
2)All of the above. We really just want their okey-dokey before we contact any guests or schedule dates.
3) Not sure how to answer. Though I would enjoy it if we made this annual or bi-annual (every two years).